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—Archangel, Jack, Grunt, and Mordin Solus—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.

This mission is the actual field mission acquired after arriving to Horizon following Stop the Collectors: Go to Horizon.

The mission is initiated once Shepard arrives at the planet.

Walkthrough
Your squad should have at least one biotic. Most collectors will not have shields or armor, but some may be equipped with both.

Mission Briefing
The Illusive Man will give Shepard the information he needs for the attack. 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 (depending on the Virmire decision in Mass Effect) either Ashley Williams or Kaidan Alenko to help get the turrets functioning. Horizon is subsequently attacked by the Collectors after the arrival of Williams/Alenko. The Illusive Man gains an intelligence warning of the attack and dispatches Shepard and the team to stop the Collectors.

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. Ashley/Kaidan will try to provide cover but ends up getting stung and incapacitated themselves. The colonists run for cover as the swarms sting more and more people.

Arrival On Horizon
Landing on Horizon, you find that the collectors are in mid-operation, they have started moving colonists into their ship. Now your job this time is to hit them and stop them before they get away. As you move away from the landing site, whether or not you brought him along, Mordin will say that tell you that the system 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. Also watch for the fragile crates in the area, there are quite a few of them. 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 like to melee you 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 by your squadmates or yourself. Once the collectors and husks fall go into the building on right for a datapad worth 4200 credits, then move on.

The next thing you come across is a dead collector, which can be scanned 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 you 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, more collectors will spawn so move around this area collecting items and equipment. There is a medkit in a building to the left of where you entered this area. 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 collectors 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 target the others so he can’t do it again. He can only possess one collector at a time but he will 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 in building 6, immediately to the north of the Particle Beam's location. Then 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 where the enemies come from. 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 an attack that is like the shockwave power and is obviously powerful and with Harbinger making an appearance every now and then, 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 on the upper level a computer for 3000 credits. To the right is a dead collector that yields another research: hyper amp. 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 what will happen in a few minutes. 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, to the north is a crate of heavy weapon ammo, take it only if you need to. The south holds a medkit, again don’t take it if you don’t need it.

Once you have everything, or you left it for the upcoming fight, if it wasn’t obvious enough, but don’t forget to grab them at some point or your lose them, move to the transmitter. A conversation will start where you can unlock the transmitter to allow 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 be collectors, husks, and Harbinger. Move around from cover to cover reacting to the enemies that come from everywhere. Focus on the husks first because they will bum rush you and melee you to death. The focus on the collectors once you take down Harbinger. Also watch out for Collector Guardians because they will deploy a shield, much like the cover shield from Halo 3, to protect themselves. Move around them rather than shooting out their shield, it goes much faster. 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. The best thing is to stay in cover and put your squadmates in cover and focus on what the enemy is doing, and keeping them off your flanks.

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

The Praetorian
Once the collectors get whittled down and the lasers near full charge, Harbinger sends in a Praetorian. A Praetorian is a deadly enemy, but this time there is no other enemies that you have to deal with, just a flying tank. The Praetorian has two deadly attacks, Death Choir and its particle beams. The Praetorian itself has just two levels of defense, barriers and armor. Defeating it 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 kill 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 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 heal. Once it takes off again open up. Repeat this process until the Praetorian collapses in on itself in mid air, and dies.

After the Fight
After the battle is over, Shepard meets with Williams/Alenko. If Williams or Alenko had been a romantic partner in ME, a brief cut scene plays showing their reunion. The mood quickly changes when Williams/Alenko discovers that Shepard is working for Cerberus. Williams/Alenko reveals that she/he had been dispatched to Horizon in part to learn if Cerberus was behind the attacks on the colonies. Williams/Alenko is highly upset about Shepard's Cerberus connection and refuses to join Shepard's mission. From the conversation you can 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 will auto 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 he had leaked information that Shepard was alive and working with Cerberus. The Illusive Man then lets slip that he allowed the collectors to attack the colony. Pick your response to that, and he comes to a conclusion. Attacking the SSV Normandy, the pursuit of humans, and attacking a colony where one of Shepard’s former squadmates was located, makes it clear that the Collectors are after Shepard in particular. At the end he says that he will find a way to get past the Omega 4 Relay. He also states that the team is not complete and they need to be focused on the mission. He hands over three more dossiers for new squadmates.

The next part of the game is more recruitment and this is where the loyalty missions start, see Kelly and your journal for more information on which ones are available and from who.

Enemies

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

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.

Mission Summary

 * 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/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.