Horizon (mission)

The Illusive Man has received information about a potential Collector attack against the small colony world of Horizon.

Acquisition
After acquiring the first four team members &mdash; Archangel, Jack, Grunt, and Mordin Solus &mdash; Shepard will be unable to select a new destination for the ship. Both Kelly Chambers and Joker, if you access the galaxy map, will inform Shepard that the Illusive Man wants a chat. Shepard must go to the FTL comm room to talk to him and begin this mission. Note that, if the player has the requisite Downloadable Content, it is possible to acquire both Zaeed and Kasumi before acquiring the four teammates mentioned above; this allows Shepard to have as many as eight team members (including Jacob and Miranda) before the mission on Horizon begins.

This mission is the actual field mission acquired after arriving on Horizon following Stop the Collectors: Go to Horizon. It begins once Shepard arrives on the planet.

Walkthrough
Your squad should have at least one biotic, such as Miranda, who has warp. Most Collectors will not have biotic barriers or armor, but some may be equipped with both. On Hardcore and Insanity, all enemies will possess some form of protection. Plan accordingly.

Mission Briefing
The Illusive Man will give Shepard information about the mission. Shepard agrees to go to the colony in order to save it. After talking with the Illusive Man, Shepard walks to Mordin’s Tech Lab to ask him if he has developed a countermeasure to the seeker swarm. He will reply yes and show Shepard the schematics.

Horizon Before Normandy’s Arrival
Horizon had been recently fitted with GARDIAN laser turrets which were provided by the Alliance to defend the colony. The turrets, however, could not be calibrated correctly, and so the Alliance had sent either Ashley Williams or Kaidan Alenko to help get the turrets functioning, depending on the Virmire decision in Mass Effect.

The Collectors attack Horizon after establishing a communications blackout. While your former squadmate is talking with one of the colonists, Lilith, the Collector Cruiser drops into the atmosphere and the seeker swarms are released. The former squadmate will try to provide cover but ends up getting stung and incapacitated. The colonists run for cover as the swarms sting more and more people.

Arrival On Horizon
Landing on Horizon, you find the Collectors in mid-operation: they have started moving colonists into their ship. Your job this time is to hit them and stop them before they get away. As you move away from the landing site, Mordin will tell you that his countermeasure for the swarms may not work because they haven’t had a decent test yet. With that reassurance, move on and after rounding a corner, engage the enemy.

Keep behind cover, move around and take out the attacking Collectors in a surprise assault. Don’t move forward too quickly, as more reinforcements will come in by air. Once all the collectors are down, move on, but pick up the heavy weapon ammo in the middle of the area where the Collectors were. Beyond that, hack the datapad on the picnic table for 6000 credits and then move on down the path

The next area that you come across will have several buildings around, and Collectors who just happened to be harvesting. Move into cover and take them out quickly. Several husks are also present. Remember, they only have melee attacks, so shoot them at a distance. A good way to end this fight quickly is to use the buildings on either side to flank the Collectors with your squadmates or yourself. Once the enemies fall, go into the building on right for a datapad worth 4200 credits. Outside the building is a dead Collector, which you can scan for a Heavy Skin Weave upgrade.

Around the corner is a dead husk. A cutscene will play and Shepard will describe how they are different from the ones encountered on Eden Prime, or Mass Effect in general. Shepard and the squad realize that the Collectors must have come with these husks and not created them on site. At the end Shepard rallies the squad, and they move on to prevent more abductions.

Enter the next area slowly and put your squad in cover if you wish. Before you do so run up the stairs from where you enter to bypass a wall safe for 4800 credits. Once that is done, move into cover and take out the attacking Collectors. Use cover and the buildings to flank the enemy to make things go a little bit faster.

Once the battle is over, do not go past the pods further up or where the path narrows as more Collectors will spawn. Instead, move around this area collecting items and equipment. You will find a med kit in a building to the left of where you entered. Move across from that building to where you see some colonists in stasis on some stairs. Continue up those stairs to find ammunition and a computer in the room at the top for 3000 credits. Going down, look in the center of where you just fought to pick up the Collector Particle Beam heavy weapon. Once you are ready, save your game and go beyond the choke point.

As soon as you past it, more Collector troopers will arrive via airborne infantry. Here, Shepard will encounter Harbinger for the first time. He will assume control of other Collectors and direct the battle, often taunting Shepard. He is more formidable as he has barriers and armor, but no health. Any time he possesses a Collector, take him down first, then quickly target the others so he can’t do it again. He can only possess one Collector at a time, but he will typically possess a Collector that is almost dead and make it beyond full strength again. Move around this area for cover and use it to eliminate your foes. Once they are down move around and recover the power cells in a building to the west and a computer containing 3000 credits immediately to the north of the Particle Beam's location. Move to the large doors to the south and bypass them to enter the structure.

Garage
Once you move inside far enough you encounter an unharmed colonist, the local mechanic. You can get some information about the attack, where your former squadmate is, what towers were installed and his anger at the Alliance, and you can earn some morality points as usual. You determine from the conversation that the GARDIAN laser towers are the key to destroying the collector ship. Once you are done he will tell you to move to the spaceport to get the towers operational.

Once you finish your conversation use the weapons locker in the garage if you want, but don’t forget to pick up the platinum, medi-gel, and bypass the wall safe to get 6000 credits. Move towards the door and beyond. Save your game before leaving.

Get to the Starport
The next area is difficult because of the lack of cover and the enemies' spawn points. As you near the edge of the wall to the right, move into cover and position your squadmates where you can cover them or vice versa and take out the attacking Collectors, husks, and scion. A scion has a powerful attack similar to shockwave, and Harbinger also makes an appearance every now and then, so take out the Scion first.

Once the enemies have fallen, move around and collect the clips that they dropped. The area also contains some power cells on a walkway to the left of the entrance and a computer with 3000 credits on the upper level. To the right is a dead collector that yields hyper-amp research. Once you have these items, move to the doors of the Starport, save the game, then bypass the doors and enter the Starport.

Starport
Move to cover and be prepared for a husk mass attack and two scions. At this point it is good to save your heavy weapon ammo because of the enemies that you will encounter later. Move around and use cover, melee attacks and powers to take out the attacking enemies. Once the enemies have fallen and before you go to the transmitter, make note of a crate of heavy weapon ammo to the north; take it only if you need to. The south holds a med kit &mdash; again, don’t take it if you don’t need it.

Once you have everything, or you left it for the upcoming fight, move to the transmitter. Shepard will ask EDI to realign the lasers and bring them online. However, there is a hitch: the lasers will take time to charge, so you have to defend the tower prepare for a hard fight.

Defend the Tower
This fight will be hard, because enemies will come from everywhere. They will include Collectors, husks and Harbinger. Stay mobile and focus on the husks first. Focus on the Collectors once you take down Harbinger. Also watch out for Collector Guardians, who will deploy shields much like the geth barriers in Mass Effect to protect themselves. Flank rather than shooting out their shield. Once one wave is down, move around to combat the next, but don’t stay in one place for too long because the enemy will flank you and take your down. Stay in cover, put your squadmates in cover and focus on keeping the enemy off your flanks.

EDI will keep you up to date on the status of the lasers, and once they reach 100 percent, you know the fight is almost over. However, there is one more problem.

The Praetorian
Once the Collectors get whittled down and the lasers are near full charge, Harbinger sends in a Praetorian. A praetorian is a deadly enemy, but it is the only opponent you have to deal with for this fight. The praetorian has two deadly attacks, Death Choir and its particle beams. The Praetorian itself has just two levels of defense: barriers and armor. This enemy is why you saved your heavy weapon ammo.

Move around. Cover is not as important because the Praetorian will flank you faster than you can harm it; just stay out of its line of fire. Fire on it until its barriers drop, then open up with your heavy weapon until it glows and slams to the ground, this is the death choir and it can kill you if you are close enough. During this time, when it is on the ground and glowing, DO NOT shoot at it because you will waste your ammo. This is a good time to revive squadmates and recharge your shields and health. Once it takes off again, open up. Repeat this process until the praetorian disintegrates in midair. Additionally, a decent strategy (especially on insanity mode) is to run circles around one of the trucks located in the area. The cover is high enough that the Praetorian's particle weapon will not hit you if you stay close enough, and you will get enough open shots to do decent damage (incinerate is extremely useful here to fire around the corners).

An alternative method for defeating this praetorian is via use of the M-920 Cain "Nuke Launcher" heavy weapon. On lower difficulty settings, the Cain is able to one-shot the praetorian, and even on higher difficulty settings, it can be combined with the Geth Plasma Shotgun to two-shot it. When playing on Hardcore or Insanity, it will help, but the Cain becomes only one part of a longer battle strategy, and you may be better off with another weapon entirely. That said, to use the Cain, you must first unlock it before reaching Horizon. This requires 3 Heavy Weapon Ammo upgrades. The first is attained on Freedom's Progress and the second can be bought from Kenn's Salvage on Omega. However, the third must be obtained by choosing the Paragon path during Zaeed Massani's Loyalty Mission, so if you choose the Renegade path (which leads to an Assault Rifle Damage upgrade) then the Cain will be unavailable and you cannot use this strategy. Once you have attained it, start the mission without it, using a weapon with decent ammunition capacity instead. Weapons like the Missile or Grenade launcher work best for this. Keep in mind you should still have 80% of your ammo or more when you reach the Mechanic - any less and you will not have enough to fire the Cain. When you reach the Mechanic (and the nearby weapons locker) switch to the Cain and proceed to the Antenna. At this point, if you are an infiltrator or vanguard, you have two options - otherwise only the first option is viable. Your first option is to fire the Cain immediately, aiming where the Praetorian is about to land. This has the advantage of hitting it (and potentially killing it) before it gains its shields (the Praetorian has only armor until it does its first Death Choir, not shields.) On the other hand, this runs the risk of bad timing - shoot too early and the Praetorian won't be in range when the Cain goes off, shoot too late and it will already be en route to your position and escape the blast before dying. If you are either an Infiltrator or Vanguard, you have another tactic available for use with the Cain, and it varies based on which class you are. If you are an Infiltrator, wait until you have some distance between you and the Praetorian and it is directly over one of your squadmates. Start charging the Cain and immediately trigger your Cloak. The Paretorian will focus on your squadmate - i.e. it will stay still in one place - for about 5 seconds before it kills off the squadmate. During this time, your Cain will finish charging and hit it. This method not only allows you 1.5 to 2 seconds to ensure you have your aim right, it also increases the already massive damage of the Cain even farther, because Cloak buffs all damage, including this. (Many people are confused by this - the Infiltrator class talent only provides slow down for sniper rifles, but the cloak talents buff everything.) The Vanguard analog to this is to run in near the Praetorian, causing it to use its Death Choir, and then storm back outside the area of effect damage radius before it hits you. Immediately swing around and start to charge the Cain. If you get the timing just right, the Cain should kill the Praetorian just barely after it starts to move again. You probably won't be outside the Cain's blast radius, but you'll be close, and the Cain's damage is weaker farther away from the source. Your Tech Armor, Shields, and Health combined should just barely be enough to survive the blast.

After the Fight
The activated GARDIAN towers hammer away at the Collector cruiser, forcing it to retreat with about one-third of Horizon's populace. After the battle is over, Shepard meets with the former squadmate. If Williams or Alenko had been a romantic partner in ME, a brief cutscene plays showing their reunion. The mood quickly changes when the former squadmate discovers that Shepard is working for Cerberus. Williams or Alenko reveals that he or she had been dispatched to Horizon in part to learn whether Cerberus was behind the attacks on the colonies. The former squadmate is highly upset about Shepard's alliance with Cerberus. Williams or Alenko question Shepard's loyalty and refuses to join Shepard's mission. From the conversation, you learn about what has happened over the last two years and what Shepard missed while being on an operating table.

Once you are done, you automatically return to the Normandy.

Normandy
You are immediately taken to a holo-conference with the Illusive Man. He is impressed that Shepard's squad managed to stop the Collectors from destroying the colony. However, Shepard is not pleased to discover that the Illusive Man had leaked information on Shepard's relationship with Cerberus. The Illusive Man lets slip that he allowed the Collectors to attack the colony.

The Collectors have made clear, through their attacks on the SSV Normandy and human colonies &mdash; particularly a colony where one of Shepard's former squadmates was located &mdash; that they are after humans in general and Shepard in particular. The Illusive Man says he will find a way to go through the Omega 4 Relay and adds that Shepard should keep building the team. He hands over three more dossiers for new squadmates.

E-Mail Message (Can you help?)
Upon completion of mission at Horizon, Commander Shepard receives this letter from a colonist. The Alliance soldier mentioned in the letter can either be Alenko or Williams.

Enemies

 * Collector Drone
 * Collector Assassin
 * Collector Guardian
 * Harbinger
 * Husk
 * Scion
 * Praetorian

Mission Summary
Collectors escaped with approximately one third of Horizon's population. Front corporation will funnel supplies, monetary aid to colonial survivors. Collector leader, Harbinger, demonstrates a personal interest in Shepard. Unclear whether his ability to possess his minions is cybernetic override, indication of hive mind among Collectors, or even Reaper technology at work. Salvage teams captured Collector bodies for study.
 * Experience gained: 1,000 (1,250)
 * Total Credits: 60,000
 * Cerberus Funding: 30,000
 * Credits Found: 30,000
 * Acquired weapons:
 * Collector Particle Beam
 * Upgrades
 * Heavy Skin Weave (Lattice Shunting)
 * Biotic Damage (Hyper-Amp)
 * Resources
 * Platinum: 2,000

Trivia

 * Speaking with the mechanic, he says that a colonist named Sten was kidnapped in the Collector attack on Horizon. This could be a reference to the character Sten in another Bioware game, Dragon Age: Origins.
 * If Williams or Alenko had been a romantic partner in the original Mass Effect, Shepard later receives a message from her/him apologizing for her/his reaction, and expressing a desire to possibly continue the romantic relationship at a later time.
 * The track of the same title (assumed to be the non-combat music for this mission) is very similar to the music that plays after the player character's death in Mass Effect (assuming you sit at that screen for a significant period). This motif is also apparent in the track Humans Are Disappearing. Needless to say it is supposed to evoke feelings of tragedy and loss.