- See also: Stop the Collectors
The true nature of the trigger for this mission is not fully understood, as there are a few reports of players completing more than five missions before triggering this mission, but it usually works like this:
- After the mission on Horizon, a five-mission countdown begins, after which Shepard will be unable to access the Galaxy Map and instead must report to the briefing room to speak with the Illusive Man, who will dispatch Shepard to investigate a disabled Collector Cruiser. At that point completing the mission becomes the only way forward.
- Even N7 assignments (e.g. "anomalies") count as a mission, so pick your five missions carefully.
- If the fifth mission is one of the two loyalty missions on Tuchanka or the Citadel, you can complete the other one before returning to the Normandy SR-2. Because of the order and tempo with which loyalty missions are acquired, the second Citadel mission will only become available in time if you leave Grunt in his tank.
- Finally, it is theoretically possible to complete Miranda's loyalty mission fifth and then recruit Thane or Samara as an extra mission, but only if Jack's loyalty mission has not yet been completed (because while Miranda's mission normally ends back on Ilium, if Jack is loyal then Shepard returns immediately to the Normandy for their argument).
- This mission will not trigger until eight squad members have been recruited, and indeed the official Prima Publishing Collector's Edition guide states explicitly (p. 114) that the story will not advance without eight squad members. Grunt does not count as a squad member until he is awakened from his tank. The addition of Kasumi and Zaeed in DLC packs, along with the ease of recruiting them, tends to make this condition moot for many players unless they delay waking Grunt.
Note: Though you'll have no choice but to complete this mission once it appears, any other missions that you didn't get to by this point can still be done afterwards.
If you have a hard time with this mission, arguably the most difficult in the game for the level you are when you reach it, one strategic way to prepare for it is to do as many missions as possible before undertaking it, and you must plan for this well before Horizon: do as many side assignments as possible, and all of the available DLC missions before completing the recruitment of all four of Mordin, Jack, Grunt, and Garrus. Then, following Horizon do four missions (perhaps including Lair of the Shadow Broker which gives more experience) and then go to Tuchanka and stay for both Mordin and Grunt's loyalty missions without returning to the Normandy thus getting an extra mission on the clock. Planning this way ensures that you reach this mission at the highest possible level with the most possible abilities and upgrades.
However, there is a countervailing approach: the special weapon or extra weapon training you get at the beginning of this mission can be a huge power spike especially for the classes normally limited to only pistols and SMGs, so you may want to consider "rushing" to the Collector ship to unlock the new weapon training as soon as possible. This can be accomplished in the following way:
- Recruit all four of Mordin, Jack, Grunt and Garrus as soon as the recruitment missions become available without completing any other missions.
- Complete the mission on Horizon.
- Complete 5 of the missions within the Firewalker Pack and/or Normandy Crash Site free DLC, which involve virtually no infantry combat.
The above will get you to the Collector ship to get the special weapon or training and have it available for as many other missions as possible. Choosing this path will make this already challenging mission even more so, but the weapon training is unlocked prior to the combat sections so you will at least gain its benefit for the fight.
One research upgrade in particular deserves special recommendation to obtain prior to this mission as it only becomes available post-Horizon: the Hard Shields research. Unlocked only after obtaining three Damage Protection upgrades, Hard Shields will reduce damage to your shield/barrier by 20% which makes a very noticeable difference in your toughness during this mission.
You will be facing a lot of barriers and armor, making Warp Ammo the most effective ammo ability in general, with Armor-Piercing Ammo and Incendiary Ammo as good followup choices both of which are more damaging to armor and health but not barriers. Incendiary Ammo can be particularly useful for its crowd control properties as most enemies will flail around briefly when ignited preventing them from attacking you. Bringing a loyal Jack as a squadmate with her Warp Ammo upgraded to be shared with the squad is one of only two ways to obtain Warp Ammo, the other is to train it as a bonus power for Shepard. In terms of damage powers, Warp is effective against both barriers and armor, as is Reave. The abundance of "bottomless" pits in the mission architecture makes physics-based attacks useful: Throw, Concussive Shot etc. can dispatch clumps of enemies with minimal ammo use given a nudge in the right direction. The M-100 Grenade Launcher also has a large force component to its shots that is capable of blasting enemies to their deaths. Flashbang Grenade is an invaluable power to have available for this mission for the same reason as on Horizon: it can disable the attacks of a familiar foe. It can be obtained either as a bonus power or by bringing along a loyal Kasumi. Either way, having it at a high level for a long duration of effect is advisable.
In terms of bonus powers choosing Barrier or one of its sister powers will increase your ability to absorb hits and allow you to instantly re-raise your shields when they go down, both of which are invaluable in key encounters. Stasis can be useful because there will be at least one opportunity to "one shot" a heavy hitter with it during a key battle. If you want to have Reave available you'll usually need to train it as a bonus power; although Samara can have it, you must have already gained her loyalty to unlock it and this is only possible if you both left Grunt in his tank and recruited her prior to this mission.
In terms of heavy weapons, the M-622 Avalanche is recommended as it can inflict high damage in a large area, possesses generous ammo capacity, and has long-lasting disabling effects. The Grenade Launcher and the Arc Projector are passable alternatives.
Cruiser EntranceMedi-gel. Up ahead is a Control Terminal next to the body of a dead Collector in a pod. Caution: A close approach will select the Control Terminal automatically.
Tip: It is strongly recommended that you create a save point here that you don't overwrite before selecting the terminal as immediately afterwards you will be given a choice that can have permanent effects on Shepard throughout both your current game and any subsequent playthroughs. If you make a choice you end up not being happy with reloading this save can give you the option of doing things differently.
When you access the terminal a squadmate makes a comment while Shepard contacts EDI, who will tell you about the experiments. Apparently, the Collectors were making fundamental "genetic comparisons between their species and humanity." Shepard can ask a question, and the conversation shifts to the Normandy's bridge where a holographic display and EDI's analysis reveals something shocking. The Collectors' DNA matches that of the Protheans! Respond to this however you choose. You can ask questions until you are satisfied, then end the conversation; Shepard then reaches down toward a pile of weapons.
Advanced Weapon Training
After the conversation, a menu will appear allowing you to choose one of three weapon-training options, which enables Shepard to use the weapon in combat. If your character already has that weapon proficiency, you instead have the option of choosing a powerful, unique weapon of that class. For example, an Infiltrator will have the option to take the unique sniper rifle, or gain access to either the common assault rifles or the common shotguns. Adepts, Sentinels, and Engineers will only have options to train in the common weapons, and not the unique ones.
- Shotgun Training: Soldiers and Vanguards can choose the M-300 Claymore Heavy Shotgun instead.
- Assault Rifle Training: Soldiers can choose the M-76 Revenant Light Machine Gun instead.
- Sniper Rifle Training: Soldiers and Infiltrators can choose the Widow Anti-Material Rifle instead.
Warning: The training carries through for each new game: you do not get to pick another weapon or additional training on subsequent playthroughs with the same character, so choose wisely. New characters on their first playthrough will always be able to pick a new option.
Caution: Even though the advanced weapon training doesn't apply to squadmates, their loadouts can still be affected by your choice. For example, if Shepard chooses shotgun training, this will automatically equip Shepard with the default M-23 Katana shotgun and also changes the shotgun of any shotgun-armed squadmates to the same. A nearby Weapons Locker allows you to change your squad's weapon loadouts as well as your own so make sure everyone's carrying what you want before proceeding.
Grab the crate of refined element zero (+250 eezo) and the power cells before you continue on.
Into the Belly of the Beast
From here continue moving. You soon enter a larger room to see many pods—some still occupied—above and ahead of you, which evokes some comments from the entire squad as well as EDI, who detects no life signs in the pods (if that offers any relief). Move up some inclines and veer to the right, where you'll find some another salvageable Collector Technology (+15000 credits). Also, a Control Terminal at the end of this path will give a Damage Protection upgrade. Continue moving through the oddly deserted ship. As you walk up a long ramp, Joker comes over the comm and tells you that he and EDI discovered that this is the same Collector ship which attacked the SSV Normandy. Shepard makes the comment that this is too much of a coincidence.Terminus Systems and still not have enough captives to fill all the pods; the Collectors must have one ultimate target: Earth. Now you have yet another reason to stop them, if you didn't have enough already. Move along until you approach an apparent dead end, where one squadmate will take note of a Command Console and the other will ominously wonder about the absence of Collectors. SAVE before you access the console.
AlertCollector General briefly appearing in the form of a red hologram, causing Joker to respond uneasily. Back to Shepard, the whole ship shakes as strange things begin happening around the squad, and the Commander radios for a status report. Joker responds that there was a power surge, and EDI says that she managed to divert the overload to non-critical systems. Worse, she informs Shepard that this was not a malfunction; it was a trap. The platform suddenly flies into the air, confusing the squad, and EDI reports that she's having difficulty maintaining the connection: "someone else" is in the system. When the platforms stops in midair, everyone loses their balance and one squadmember is knocked down. Your squad recovers as EDI says that she has reestablished connection and needs to finish the download before she can override any systems. She will keep you updated on the progress, but it is really finished when you defeat all the Collectors that are coming in fast. So take cover and prepare for a hard fight.
Sky High Battle
The platform you are on provides some cover and a good position to combat the enemy. Two Collector Drones and a Collector Guardian are the first to drop in; if you can, take them out as fast as possible to prevent Harbinger from possessing them but this can be difficult on higher difficulties. A platform with a Scion stationed on it will arrive in the first wave and slowly orbit the main platform cluster while you combat the other Collectors, continuously firing its signature shockwave attack that can devastate you and your squad. As the battle progresses a second Scion will eventually show up on another orbiting platform as well. You will have to fight a total of three waves of Collector troops who each show up on their own platform that docks with your starting platform. Move from cover to cover as needed and don’t forget to manage the health and abilities of your squadmates. Focus on the Collectors before going after the Scions as they are a more immediate threat, and in the case of Harbinger, a mortal threat if not dealt with quickly. However it's important to keep track of the Scion's positions and to take cover from their attacks as much as possible as they deal a large amount of damage, can stagger you out of cover, and can also delay your shields from recharging with direct hits (a bluish residue will cover you if your shields are disabled in this way).
Insanity Combat Strategies: On lower difficulty settings many play styles will work here, but of all the Mass Effect 2 missions, it is perhaps the first battle of this mission that strikes the most fear in the hearts of Insanity level players. Fear not, however, as there are some straightforward methods for dealing with it. The following list is intended to help players having a hard time getting through this on Insanity, but many will of course work on lower settings as well.
- Taking cover with your squad in the center of the three segment crescent-shaped cover on your starting platform might seem like the best option but in fact it's a death trap. A far safer strategy is to place your squad in cover here (placing both squad members in the center segment is best) while you take cover at the forward edge or lip of the platform away from the squad. Being in front of your squad in this way will cause the Scions to focus their attacks on you more often than on your squad which will drastically increase your squad's longevity (though stray Scion shots may still hit them occasionally due to their large area of effect). This cover position is also completely safe from Scion fire for Shepard as long as you are crouched down and sometimes even when you aren't. Huddling up shoulder to shoulder with your squad on the other hand is strongly discouraged as it maximizes the chances of everyone getting leveled by the Scion's attacks.
- If you have Stasis as your chosen bonus power you can use it to efficiently dispatch the Scions as with proper timing you can freeze them in place while their platforms continue to move, causing them to fall to their deaths after the freeze wears off. Be aware however that killing one of the two Scions triggers the last of three total platforms of Collector troops to arrive. If you don't have Stasis, then defeating the Scions will have to take a back seat to keeping Harbinger off your platform and killing the Collector troops attacking your squad. If you have one available, tie up one of the Scions with a Combat Drone; otherwise attend to killing them whenever you have a lull between Harbinger/Collector waves. Note: Stasis does not work on Harbinger.
- Heavy weapons exist for tough battles and it's tough to find a battle harder than this one. If you've done a good job of saving your heavy weapon ammo and upgrading its capacity prior to this mission, there is absolutely no reason you should hold back here - pull out the big guns and go to town on the Collectors with extreme prejudice! The Arc Projector, Avalanche, and Grenade Launcher are all fairly easy to aim, hit in a large area, and disrupt/disable as well as damage targets, making them ideal here. The other advantage of heavy weapon spamming in this way is that it keeps your squadmates alive more effectively. Also, it's possible for Harbinger to spawn from a Collector that is knocked down or frozen, which can also mean he will be stunned or even frozen for the duration too, even though normally Harbinger is immune to such effects.
- You can avoid having to fight Harbinger at all in the first wave if you can kill all the Collectors before he spawns from one. Heavy weapon spam is the most effective way to do this on higher difficulties as the Collector's barriers are too tough to get through quickly enough otherwise; once their barriers are down using force-based powers to fling them off the platform to their deaths is your best bet.
- When Harbinger throws his slow-moving "singularity," draw it away from your cover so that it will miss, because if it hits, Shepard will be knocked from behind cover and exposed to potentially deadly fire and that cover position will become temporarily unusable.
- It's very important to prevent Harbinger from closing to point blank range (which he will try to do), so concentrate your fire on him especially when he gets close. You don't want him flanking you on your platform and driving you out to a bad position, particularly where the Scions have clear shots at you. Getting cornered in this way is probably the most common way to die during this battle. The charged shots of the Geth Plasma Shotgun are one of the fastest ways to eliminate Harbinger's barrier, at which point you should switch to anti-armor weapons and powers to finish him off. Note: your squadmates will be preoccupied with shooting at the Scions so if you want their help in attacking Harbinger you will have to manually order them to do so.
- Having Flashbang Grenade available as a bonus power or by having a loyal Kasumi in the squad can drastically reduce the difficulty of this mission and the opening platform fight in particular as it disables all of Harbinger's attacks for the duration of its effect. It's possible to keep Harbinger disabled indefinitely with a high enough level Flashbang, turning arguably the greatest threat to you into a non-factor. Keep in mind however that Kasumi's Flashbang can't help you if she herself isn't alive to use it.
- Always revive your squadmates as soon as they fall or even if they are in the red - they create distractions for the enemy that will keep fire off of Shepard. Don't "conserve" Medigel during the arguably hardest battle of the game. Keep in mind also that Medigel, if sufficiently upgraded, can restore the shields of Shepard and the entire squad making it effective at counteracting the shield recharge delaying effects of Scion attacks on a relatively quick cooldown compared to a bonus power such as Barrier.
- Bring squadmates with abilities upgraded to disrupt enemies in a large area. An ability that gets an enemy off its feet (such as Slam, Pull or Throw), can be used when the platforms carrying the Collectors are moving in. If a Collector with no barrier is knocked off its feet when the platform is still moving, chances are pretty good that it will plummet to its death when the platform moves away. Crowd control abilities also reduce incoming enemy fire increasing the longevity of Shepard and the squad. If you combine squad disruption abilities with Shepard blasting away with a heavy weapon, you can quickly overwhelm the groups of attacking Collectors before they overwhelm you.
Once all the Scions and Collectors are down, EDI radios that if you access the panel again she can regain control.
Note: Before accessing the panel, pick up clips and some power cells located on one of the platforms that flew in during the battle.
Access the panel to continue. You are rewarded with a ride before more action, during which EDI explains that the distress signal originated from the Collector ship contains an error that clearly identifies it as a non-turian signal. She further explains that it is not possible that the Illusive Man would have been fooled by it, since she discovered the error using Cerberus detection protocols which he wrote. The conclusion is that he knowingly sent you into this trap. Respond to that in any way you wish. Joker will then interrupt to tell you to hurry up because the cruiser is powering up its weapons. He will keep you updated over the course of the rest of the mission about their progress.
Fight Your Way Out
As you land get off the platform and move. You'll enter a small room with closed doors, one of which EDI will open for you; grab the med-kit with Medi-gel, and head through the open door. Warning: Once you go through the door and drop down, the door slams shut behind you and you are unable to go back.
Soon you come to a close encounter on level terrain, just beyond some salvageable Collector Technology. Slam into cover at the first chance and shoot out the Collector drones that fly in; one of these will be quickly possessed by Harbinger. Focus on taking out Harbinger then focus on the other fodder in the room to prevent it from doing it again, or, if you wish, command your squadmates to attack the Harbinger while you kill the remaining Collectors. That way the Collectors should all die right about the time your squadmates polish off Harbinger.
Combat Strategy: Place your squadmates into cover kneeling down high up on the ramp near the door that just closed behind you. Move Shepard down to the flat area to trigger the Collectors. Quickly back Shepard up and place him into cover behind the left side pillar that contains the salvageable Collector Technology. From this cover, the Harbinger and Collector Drones will not move forward beyond cover and won't shoot at Shepard. Be warned though, do not have Shepard shoot from this cover! There is some sort of invisible barrier around the pillar and your shots hit that "barrier". Shepard will have trouble using powers from this cover as well. Use your squadmates up on the ramp to throw powers to chip away at the Collectors until they drop.
Alternate Strategy: As mentioned previously, having a high level Flashbang Grenade power available (usually by having a loyal Kasumi in your squad) makes this fight a cinch as you can disable Harbinger's attacks continuously with it, rendering him harmless. Focus on the other Collectors while he is disabled and then take him out last.
After you put down these enemies, grab the salvageable Collector Technology (+7500 credits), and move down a ramp to a larger and more complicated room for another Collector encounter.
In this next area you really have a fight on your hands; however, there is a lot of cover to take advantage of. Note the ramp on your left (as you enter), which leads to an elevated section stretching the length of the room; this section is accessible on the far side of the room as well. The first wave of Collectors will arrive as you enter, more or less in front of you. But keep an eye on them because they may use that left side walkway to flank you; and watch out for Harbinger because you can bet it will make an appearance.
Combat Strategy: When you first enter this area, you will notice two ammo clips next to an unusual piece of cover shaped like part of a hexagon. This is the safest place to take cover and remain for most of the battle, as it not only prevents enemies from flanking you but also shields you from enemies up the ramp on the upper level. You can also keep your squadmates back in cover on the ramp you entered from so that they are safely out of the way for this battle. Keep Harbinger away from you of course, but if he's not an immediate threat prioritize picking off the Drones and Guardians.
On lower difficulty levels it is often possible to kill Guardians before they land, thus preventing them from setting up shields. On Insanity though this is harder to do and ill-advised as it's usually better to drop the Collector Drones first - that way Harbinger will often "kill" the tougher Guardians for you by taking them over.
- As mentioned previously, the Flashbang Grenade power can make this fight much easier as it can prevent Harbinger from attacking you. Use Flashbang to suppress him when you pop out of cover to attack the other Collector troops otherwise his attacks can stagger you and leave you easy prey.
- Having a sniper rifle can definitely make eliminating the Collector troops much easier in this fight as many of them are at long range and stubbornly cling to cover. If you don't have a sniper rifle then an accurate assault rifle or SMG like the M-12 Locust is your next best bet. Patiently wear down the Collectors one by one.
- To make it easier to land shots and powers on the Collectors ducking in and out of cover, consider using a squadmate power to briefly stun them while you line up your shot or launch your own power; even if the Collector still has a barrier, using a power like Throw or Flashbang on it will still stagger it momentarily.
- Having Barrier, Geth Shield Boost, or Fortification as a bonus power can really help on higher difficulties as you will be losing your shield a lot while trading shots with the Collectors and Harbinger. Having a tougher shield lets you trade damage more efficiently and gives you a "panic button" to instantly restore your shields if you come under more fire than you expected.
After a couple of waves, a group of Abominations will appear and should always be the first priority because of their explosive suicide attack. Burn their armor away and then throw them around with biotics. On Insanity it is not recommended to send your squad forward during this section, as they will tend to get flanked and fried. At lower difficulty levels if you allow a squadmate to move forward on the lower level, these new arrivals may attack the squadmate from their elevated position, allowing you to flank them.
In any case, once you eliminate all the enemies (you'll face 4-5 waves), head to the other end of the room and pick up the power cells, a med-kit with Medi-gel, and another crate of refined element zero (+250 eezo).
Warning: Save your game here before the drop down into the next area.Husks enter the area to block your path; second, and more alarmingly, there is a Praetorian flying at you as well. This Praetorian duel will be more difficult than the one on Horizon due to the presence of other enemies but the same principles for fighting it still apply, you just need to eliminate the other threats as fast as possible so that you can then devote all your attention to the hovering monstrosity. Review the section on the Praetorian in the Horizon mission walkthrough for a refresher on some things you should know on how to deal with one.
The general strategy recommended here is intended to work for all classes even on Insanity difficulty but feel free to experiment and come up with your own methods.
Combat Strategy: After you drop down into the area but before you move forward to trigger the fight (you'll know you've triggered it if EDI comes over the comm) make final preparations. Make sure your ammo powers are assigned how you want them, any shield bonus power is activated, and make sure you and your squadmates have the right weapons selected. Order your squad to move into the area and take cover where you want them; this will not trigger the fight. If your squad doesn't move when you order them to (they can sometimes get stuck in the elevated area before the drop down) reload your save and try again until they follow your orders properly. The optimal place for your squad is in cover near the center of the lower area away from the left wall. This location is best as they will be close enough to the Collectors and husks that will spawn to draw their attention away from you while being far enough from where you'll be fighting the Praetorian not to get hit and killed by its slamming Death Choir attacks.
As for where you'll be fighting the Praetorian: look along the left wall of the area for a large, roughly conical pillar with a wide base that twists and tapers towards the ceiling. This is the best place to play "Ring Around the Rosie" with the impending Praetorian. Once you're ready to begin the fight, advance down towards the pillar hugging the left wall and take cover behind it. First, focus on the advancing husks and the Collector drones that fly in and once the Praetorian reaches you start leading it in circles around the pillar while continuing to focus on the other enemies until they are neutralized. Using a heavy weapon is perfectly acceptable here to make killing the husks and Collectors less of a headache but conventional weapons and powers plus your squadmates works too. The Arc Projector is probably the safest choice for this because it is more consistent in eliminating the Collector Drones while simultaneously suppressing their attacks by stunning them.Warning: The Praetorian's lethal Death Choir attack triggers when it has taken a significant amount of damage to its armor or when it's close to an enemy. Experience is the best teacher for when to expect it and also for how far away is a safe distance; the important thing to remember is that Death Choir's shockwave ignores intervening cover, so merely being behind the pillar isn't enough, you also need to be a certain distance away. If you get staggered by the impact of the Praetorian slamming into the ground prior to the shockwave it might be game over.
- Be sure to revive your squadmates with Medi-gel when they fall because their weapons and powers are needed against the Praetorian and the other enemies you face. A word of caution: while Unity will heal both you and your squad to full health and shields with the right upgrades the effect isn't instant. If you're playing Ring Around the Rosie with the Praetorian and you need to use Unity make sure to give yourself sufficient lead time and stay on the move.
- The need to stay moving while fighting the Praetorian is just one more reason why having Barrier, Geth Shield Boost, or Fortification as a bonus power can pay huge dividends in this mission; if you're running from the Praetorian and your shields are down while facing additional incoming fire from the Collectors you're likely dead unless you can restore your shields immediately, and Medi-gel while powerful is still a limited resource. The Sentinel has the luxury of Tech Armor for such a situation.
- Disciplined power usage is important in this fight; having an emergency shield restoring power is useless if your powers are still recharging when you need it. It can be best to rely solely on fast-recharging powers, squad powers, and weapons until the enemies other than the Praetorian are all dead. It can also be wise to invest in power recharge time reduction bonuses from armor pieces or class passive skills prior to beginning this mission.
- As on Horizon, the Praetorian will remain focused on Shepard the whole battle with only two exceptions: activating Tactical Cloak or summoning a Combat Drone at the Praetorian will temporarily distract it, and in the case of cloaking, cause the Praetorian to decide to fry one of your squadmates instead. For this reason an Infiltrator should only use the cloak as a last resort.
- Fortunately, Harbinger will not spawn from the Collector drones you encounter in this fight, however you should still aim to eliminate them as fast as possible as their guns still hurt and they're a big threat since the Praetorian is constantly flushing you from cover. Note: your squadmates will focus all their fire on the Praetorian which can be frustrating if you want to focus on eliminating the lesser enemies first. If you want them to fire on something else you'll have to directly order them to do so.
- It is possible to stop more than a few Husks from spawning if you run to the other side of the room and reach the open door causing it to close. Once it closes, no more enemies can enter from it allowing you to focus on the Praetorian more quickly. This tactic is not recommended unless you are an Infiltrator with Tactical Cloak letting you escape back to cover. An Engineer can also get the door closed sooner by spawning a Combat Drone by an enemy in the doorway. You won't prevent that many enemies from spawning regardless of how you get the door closed so the risk/reward ratio of this tactic makes it of questionable value.
- An M-920 Cain shot can do significant damage to the Praetorian at the start of the fight as it spawns without its barrier active, but you must begin charging the shot as soon as possible after you hear EDI over the comm as you must get the shot off before anything can shoot you and interrupt the charging of the shot. This will not kill the Praetorian on higher difficulties and is not really recommended as even a Praetorian with weakened armor still has a powerful barrier so it's still generally better to eliminate the lesser enemies first before trying to take it down. Remember also that the Cain does friendly fire so keep your squad out of the blast zone.
Once you finish the Praetorian off, pick up any ammo in the area including the power cells on the lower level if you hadn't already, and move to the door. The door will close as you approach it and EDI will divert you to a longer path around the obstacle.
Warning: Once you go through the door, the door slams shut behind you, you are unable to go back, and the battle starts.
The next fight can be difficult if you rush in too fast and get flanked, but is relatively easy if you approach it step by step. The Collectors attack in waves that include everything in their arsenal except another Praetorian (fortunately). The recommended strategy is slow and methodical and keeps your squad out of the thick of the action but if you're feeling adventurous by all means try a more aggressive approach.
Combat Strategy: When the battle starts, place Shepard and your squadmates into cover kneeling down with their backs facing the door. This will be your cover for your squadmates the entire battle. Move Shepard forward to trigger the first wave and get ready. When the Abominations spawn, they need to be killed quickly with weapons or powers. All other Collectors from this point on will not come down the ramp and should have difficulty firing at your squad if placed in good cover. Harbinger will appear and several Collectors spawn in the first wave but they stay at a distance on the higher ground. Kill the enemies using weapons or powers by moving forward towards the ramp and then running back to recharge shields (this is yet another situation where having Barrier or a similar shield boosting ability can come in handy). Additional waves can be lured out by having Shepard move forward carefully then running back once enemies start flying in. This strategy takes time but you can use powers and snipe with accurate weapons from a distance and conserve ammo while minimizing the danger to yourself and your squad. As in every other fight involving Harbinger, the Flashbang Grenade power can give you even greater security by suppressing his attacks continuously.
Once all the Collectors are eliminated the final hurdle is a lone Scion who lingers by the passageway you need to take to exit the area. It won't move from this location, so you can even conserve ammo and kill it entirely with powers if you don't mind taking the extra time.
Warning: Save your game at this point before you move into the Husk battle as you will be unable to save your game until after the mission is over.
The final part of this mission involves a gauntlet of about twenty husks! Head down the lengthy hall until you hear Joker over the comm recommending that you pick up the pace which is your cue the husks are about to appear.
Combat Strategy: Keep moving so as not to get cornered while you eliminate the Husks. On higher difficulties shoot off their armor and then use force-based abilities such as biotics or Flashbang Grenade to instantly kill unarmored Husks in groups. If worst comes to worst and conventional weapons and powers aren't cutting it, take out a heavy weapon if you have one with good spread and blast away.Alternate Strategy: Although it takes some courage to attempt, you can bypass the Husks entirely by sprinting past them to the shuttle which triggers the escape cutscene. Start running the moment you hear Joker over the comm, then stop to catch your breath as you round the corner, then sprint again to get past the majority of the Husks; if you're quick about this you'll see that most of the Husks aren't really aware of you yet and aren't rushing to the attack. To make this easier, a Soldier can Adrenaline Rush past the Husks, an Infiltrator can Tactical Cloak, and a Vanguard can Charge at a Husk nearest the exit. If playing as an Adept, Sentinel or Engineer, then a few shots with the Avalanche or the Grenade Launcher will clear a path through the bulk of the Husks without a problem.
Once the Husks are thinned out or completely eliminated the way back to the shuttle is clear. Upon reaching it a cutscene will play that covers your escape and your return to the Normandy.
NormandyOmega 4 Relay, an advanced form of an Identify Friend/Foe device, or IFF. The Illusive Man tells Shepard that each Collector ship is equipped with the device. Make a comment about that. After your conversation decision, he tells Shepard that Cerberus has located a Derelict Reaper in the Thorne system of the Hawking Eta Cluster. It is in orbit of the brown dwarf Mnemosyne. He says that the vessel’s mass effect fields keep it aloft and safe, and that he has dispatched a team already to study it. You can make a comment about that. To end the conversation, the Illusive Man tells Shepard that a trip through the Omega 4 Relay will likely be a one way trip and that the team needs to be focused on their tasks in order to survive.
After the meeting Jacob Taylor, Miranda Lawson, and Mordin Solus join you in the briefing room. You can explain the Illusive Man’s actions any way you want. No matter the conversation, the general consensus is that the mission was a success. EDI comes over the comm and tells you that, based on the Collector ship’s course through the Omega 4 Relay, she can calculate the location of the Collector homeworld. She brings up a display of the Milky Way and the path ends up in the galactic core. That shocks everyone and you can make a comment. Jacob is skeptical, arguing that nothing can survive in the galactic core. Shepard notes the Collectors are merely pawns of the Reapers, and considering the capabilities the Reapers have already demonstrated with feats like constructing the Mass Relays and the Citadel, constructing a base at the heart of the galaxy doesn’t seem all that far-fetched. At the end of the conversation, you have dialogue options about whether to go after the Reaper IFF immediately or build up the team. It is strongly recommended that you continue to build up the team first, but your answer in the conversation does not commit you one way or the other.
Gathered vital intel regarding Collectors and Omega-4 relay.
With Shepard's escape, Harbinger knows our true capabilities and will have to adopt new tactics. Will have to be careful, as Harbinger's information network may rival Cerberus or Shadow Broker's. Also appears impossible to block his ability to possess minions. EDI's work was exceptional, however, proving value of shackled AI.