Legion: A House Divided

Legion has learned that the geth heretics have adapted a Reaper virus which, when updated, will compel the normal geth to join them in their war against organic life. This virus must be stopped.

Acquisition
The player will recover Legion at the end of the Reaper IFF mission and may choose to keep him onboard and activate him. Sometime after activating him, Kelly will say that Legion wants to talk. If the player has already completed every other mission and assignment, this mission will be available immediately after talking to Legion for the first time (otherwise the player would not be able to leave the Normandy to install the IFF). The geth have written a virus that would bring all geth to their side. The virus is at Heretic Station.

Walkthrough
Since Legion can use an assault rifle, and has the valuable AI Hacking and Combat Drone powers, it is recommended that you bring along someone with biotics and Overload, such as Miranda.

Heretic Station Approach
Shepard and the team approach Heretic Station undetected because of the Normandy's stealth systems. Joker remarks that should any geth look out a window they are not cloaked to the visible spectrum, however, Legion replies that windows are a structural weakness that are not present on the station. The squad boards the station.

Heretic Station Entrance
When you arrive Legion tells Shepard that there is no air and little gravity because the geth require neither. Legion then informs Shepard that there is an alternative option to the plan. Instead of destroying the station, Legion says that the virus is finished and Legion could modify the virus and bring the geth back into the main geth fold, which would stop them from aiding the Reapers. Legion is unsure about either path and when asked he needs more data before drawing a conclusion. Move down the hall, grab the medi-kit and head into the next room.

Upon entering the room, Legion will say that the geth are currently in separate nodes to clear out the excess data that Legion uploaded at the start of the mission. The green lines on the floor of the rooms should not be crossed unless you are in position to take out the geth attached to the hubs. It’s worth noting that the NPCs in your team can also cross the lines and trip the alarms as well. Move around the room and get into position before stepping on the line. Overloading or destroying the hubs sends the geth attached to it, into shock for a few seconds and allows you to make the first strike. The Geth Troopers and Geth Hunter that were attached to the node eject and attack you. It is easy to take them down before they have a real chance to hurt you. When they are down a cutscene will play and Legion will explain how the hubs work and explain the shared geth experience. You can again ask about the decision but again Legion is unsure. Salvage the hub for credits, and do so for the rest of the mission.

The next hallway contains some inactive rocket drones. Legion says that he can hack them and they will fight for about 10 seconds before they self-destruct. As you move down the hallway the door at the other end will open and some geth will spill out. Hack the drones, take cover and fight them until they fall. Move on and into the next room.

Be careful as you enter this room because there are two geth hubs. One ahead to the left in the alcove; the second is in an alcove next to the exit door. You will have to cross the lines to get into cover for this room but focus on the geth ahead of you for now. Cross the line, or overload the hub if you can, and activate the geth. Once those geth are down, make sure to take out the Geth Hunter first so it does not close in, then move to where the hub is and take out the other geth. You can also use the window of sorts on the entrance hallway for another good position for the second group. When the geth finally fall, salvage the hubs and move into the hallway.

This hallway has some Geth Troopers so use cover and take them out. When the geth fall move to the end of the hallway and grab the medi-kit. Move up the ramps to the next room. It is recommended you save before entering this room. This room contains a storage room of sorts and has little cover. Find what you can, usually along the railings on the side you enter from. There are two rocket drones in the center of the room and activate only one at a time. There will be two waves of Geth Troopers and Geth Hunters. Usually the geth would run through the center of the room, but watch out for Hunters and Troopers that will not go through the center and will go across the sides. Once you manage to take down the geth, move around the room and collect clips, you are probably low on ammo now, so take the time.

Move to the door, open it, and go in the hallway. At the other end are some power cells and a med kit, grab them both before moving down the ramps to the next area and deeper into the station. Once you are up the ramps go to the right and pick up the refined palladium and the head over to the door. Save the game before going in.

Heretic Station Interior
Once in the next room immediately take cover and combat the geth that are already in the room. There is a collection of two Geth Troopers and a Geth Hunter that will cloak once you enter the room. Target the Geth Hunter first and then the troopers. There is an inactive rocket drone in the room that can assist you in this fight. Once the geth are down the non-Legion squadmate will ask how long the room outside the windows is. Legion will say that since the station is 15km long the room likely runs the length of the station. Before leaving the room go behind where you entered to hack a terminal for a Geth Shield Boost upgrade. Move through the next door and watch out for the data lines on the floor as you move up through this room with the four massive tanks.

Once you emerge in the next room, take cover as there are two more geth hubs in the room, one to your left, and the other to the right. If you can, take out one of the hubs at a time. Use cover, powers, and whatever else you can do to get the geth to fall the fastest. Once they are down, pick up clips and then move on. The next hallway contains what appears to be a massive server room. When you pass one of the windows, you can indicate a conversation with Legion. He will explain that the room is a server room, of sorts. The massive computers do contain the some of the collective memories of these geth. Legion takes a good look and realizes just how much the heretic geth have grown from the true geth. You can comment on that and then you can ask him about the decision. He will still be unsure and a debate will be raging in the core.

Move into the next room and for once, there are no enemies. Take a moment to observe your surroundings and don’t activate any of the rocket drones yet, you will regret it in a few minutes. Move to the console in the middle, save your game, select the console, and the dialogue will come up with some options. Legion says that the virus is completed and that it must be deleted. Legion will say that while the virus is being deleted/altered, all the geth on the station will become aware of the squad’s presence and will try to stop them. Prepare for wave after wave of geth. So dig in and wait for the first wave.

Hold Position
This next area is just about killing geth before they have a chance to get to your position. There are a few strategies for winning this protracted battle.
 * Waves
 * Wave 1: Geth Troopers
 * Wave 2: Geth Troopers, Geth Rocket Troopers
 * Wave 3: Geth Troopers, Geth Rocket Troopers, Geth Hunters

Strategies for fighting the onslaught: Basically, don’t allow the geth to the upper platforms. If they do and only on the last wave use the two rocket drones because they can provide a last defense against Geth Hunters. Once all the geth are down you re-engage conversation with Legion. He states that the virus has been deleted and asks what the next step is. You can, for the last time, ask for Legion’s opinion and again he cannot decide. You can also ask why he is leaving the decision to you. He replies that you have fought the heretic geth and that is why the decision is left to Shepard. Make your choice.
 * Don’t active all the rocket drones in one wave. There will be three waves and each wave will be progressively harder.
 * There are six drones on the lower level and two on the upper level, save the upper ones for the last wave, and not until you need them.
 * Order your teammates to one of the two flanking staircases while you personally cover the other.
 * Have one squadmate cover each side and take cover in the center providing cover as necessary
 * If you choose to rewrite the geth, Legion will state that the station will release an EMP pulse to rewrite them and it will also damage any unshielded organic tissue in a large radius. The station in unshielded. Your other squadmate states that that would have been nice to know earlier.
 * This solution might present a problem down the road with the integration of the memories of the heretic geth into the geth collective.
 * If you choose to destroy the station then Legion will state the explosion will be massive and they need to evacuate quickly.
 * This problem will be a more immediate solution. This station, however, is only the main station, and there will still be holdouts, which will present problems in the future.

No matter what you choose, now you have three minutes to evacuate.

Evacuation
Once the conversation ends, the three-minute countdown will start. At the end of those three minutes, you will die if you can’t get out. Move down a hallway to the right of the console and take cover as the geth will try to stop you. Keep moving and shooting until you reach the second turn. Send your squad in first because there is a Geth Prime around the corner. Sending your squadmates in first will distract it while you can use the corner as cover to take out the Geth Prime. Watch your remaining time, because if you take too long you will die. Once all enemies are down, move across the room they were in and to the door to exit back to the Normandy. The ending cutscene will play, showing your decision of whether to rewrite the heretics or blow up the station. If you chose to rewrite, an EMP blast will show; if you chose to destroy the base, it will blow up.

Normandy


Once back on the Normandy Joker will inform you that Tali and Legion are having a heated discussion, if Tali's loyalty mission has already been completed. Once you arrive at the AI core, you see Tali holding her pistol to Legion. She yells at you that, even though she was willing to work with a geth, Legion was trying to send classified information about the Migrant Fleet to the geth. Legion states in his defense that he knows the quarians were performing weapons tests on geth and that he was trying to protect his people from a possible attack, further citing Tali's willingness to be exiled for the sake her own people as a similar action.

You can either side with Legion or Tali or you can also use a Paragon or Renegade option to get them both to agree. If you use this option then Legion will agree not to transmit Tali's data for the sake of "unit cohesion," and Tali will volunteer some non-classified data for Legion instead. If you fail either option then you will lose the loyalty of one of the squadmates.

Enemies

 * Geth Trooper
 * Geth Prime
 * Geth Hunter
 * Geth Rocket Trooper

Mission Summary

 * Summary Report Text
 * Renegade Route: Destruction of geth heretics may change entire galactic landscape. Bolstering observation of geth space to monitor any fleet movements. Regardless, data recovered from geth station offered valuable insight into AI social and technological processes. Legion should be committed to the mission after Shepard's help with the geth heretics.
 * Paragon Route: Rewriting of geth heretics will make main geth faction significantly more powerful. Given perception of Reapers, they may be possible allies, though long-term cooperation remains unlikely. Regardless, data recovered from geth station offered valuable insight into AI social and technological processes. Legion should be committed to the mission after Shepard's help with the geth heretics.
 * Experience Reward: 750 (937)
 * Legion Power Unlocked:
 * Geth Shield Boost
 * Upgrades:
 * Geth Shield Strength (Cyclonic Particles)
 * Credits: 30,000
 * Cerberus Funding: 15,000
 * Credits Found: 15,000
 * Resources:
 * Palladium: 2,000
 * Morality
 * Destroying the heretic facility grants +30 Renegade points
 * Rewriting the heretics grants +30 Paragon points

Trivia

 * When Shepard asks about how the virus works, in the first conversation, Legion will respond with; "An equation with an result of 1.33382 returns as 1.33381. This changes the result of all higher processes. We will reach different conclusions." This is a reference to the Pentium FDIV bug.
 * During Legion's attempt to find consensus, Legion states that it has 573 processes voting for re-purposing the virus and 571 voting for destroying the station, leading to a total of 1,144. This is 39 fewer than the stated total of 1,183; since Legion mentions earlier that its high-level processes had not reached consensus, one possibility is that some of its lower-level processes do not participate in this decision. Alternatively, it may be that those 39 processes are still "on the fence", or perhaps even abstaining - that is, if the geth have such a concept.
 * When hacking turrets aboard the station, Legion occasionally utters "Executing sudo command." This is likely a reference to the common Unix command sudo, which is used to issue a command as a different user, typically administrator or root.
 * It is believed that completing this mission will have a major impact on the story in Mass Effect 3, as the heretic geth were major allies of the reapers.