Some time after recruiting Tali, Kelly will tell Shepard that Tali seems distraught after receiving a message. Shepard learns that Tali has been accused of treason, and that she must return to the Flotilla to defend herself. Tali provides the current location of the Migrant Fleet.
There is a very extensive set of unique dialog all over the place, both with characters you directly interact with and the casual NPC conversations of people you walk close to, if you have Legion in your party and are able to convince Captain Kar'Danna to keep him along. But since you get Legion during the Reaper IFF mission which starts a countdown to the Suicide Mission, if you want to bring Legion along and properly engineer your crewmates' survival chances you will have to time this very carefully. Finish up on as many outstanding dossier/loyalty missions you wish to do before obtaining the Reaper IFF, then immediately start this mission afterward and bring Legion along.
As for the combat mission where you try to retake the Alarei you'll be facing a ship full of geth that will shoot on sight. You'll have Tali with you by definition, and be sure to allocate plenty of points to her AI Hacking power which will help keep the geth fighting themselves instead of you.
In terms of squadmate powers, Overload is very helpful here, as a lot of the geth are normally shielded even on lower difficulties, so it is recommended that you select third squadmate who can use the power. This will make the whole fight on the Alarei noticeably easier. Also, equipping yourself and your allies with Disruptor Ammo, if available, will greatly increase your squad's combat effectiveness.
Because of the close-quarters nature of the area, shotguns provide more of an advantage than most weapons.
The Rayya Edit
At the garden plaza where Tali is to be tried, Admiral Shala'Raan greets Tali as "Tali'Zorah vas Normandy". Tali hugs the Admiral, calling her "Auntie Raan," and then introduces the Admiral to Shepard as a friend of her father. Tali realized that she was called "vas Normandy". She has been stripped of her quarian ship's name. Shepard is recognized as the captain of Tali's ship. Because of that, Shepard is Tali's advocate in the hearing. Shepard's reaction to being Tali's defense lawyer can garner 2 Paragon or Renegade points. The hearing starts. Shepard may use Charm or Intimidate in two separate dialogue choices to gain morality points. The admirals sandbag Tali with the revelation that the lab ship Alarei has been overrun by geth. Tali's father, who was aboard, is assumed dead. Tali's immediate concern is her father's safety. Shepard and Tali propose to re-take the Alarei. The hearing is recessed pending the recovery of the Alarei and any data that might reveal what truly happened on it.
The Alarei Edit
Shepard and the team take a shuttle from the Rayya to the Alarei. Shepard enters a room that has two Geth Troopers. They are quickly reinforced by more Geth Troopers and two Geth Hunter. The key here is not to have the ever-advancing cloaked Hunters reach point blank range, because their shotguns are deadly.
Combat Strategy: Since you have Tali in your party, her AI Hacking ability can be most useful in keeping a Geth Hunter at bay. In addition to the obvious possibility of using it on a de-shielded Geth Hunter, it can be used on a Geth Troopers standing near a Geth Hunter and will tend to cause the Geth Hunter to become distracted and even move away from you. Since Geth Troopers are much easier to shoot the shields off of than Geth Hunters, this tactic will come in handily repeatedly throughout the entire mission. Understand that this battle will be close quarters with many geth and they close quickly. Do what you have to do to take them down quickly or you'll be overrun.
In the room is a med-kit with Medi-gel, a laptop (+1500 credits), a second laptop (+1800 credits), power cells, and a Quarian Log. The Quarian Log when accessed shows a quarian scientist reporting that something is slowing down the systems, so they're taking down the firewalls; Admiral Rael'Zorah ordered them to bypass standard safeties.
Down the hallway is a medbay. In the medbay is medical station with Medi-gel, a hackable Terminal (+4200 credits), and a Repair Drone that Tali had sent to her father. Tali talks about what geth parts she sent to her father and how she did it when you access the Repair Drone.
Continuing down the hallway there is a small office with a hackable Monitor that awards a Geth Shield Strength upgrade. In the hallway between the medbay and the small office is another Quarian Log. The Quarion Log when accessed shows a quarian researcher realizing that geth have infiltrated their computers.
Shepard can continue through the door into the next room but beware as a Geth Hunter comes down the stairs from the rear and right of the room so take the Geth Hunter out quickly.
In this room is a laptop (+1800 credits) and a second laptop (+2100 credits). Near the stairs upwards is a Wall Safe (+4200 credits) that can be bypassed and another Quarian Log that shows a researcher's last moments before being overrun by the geth.
Note: Save your game at this point before going up the stairs as the next battle will again be close quarters combat.
You can then go up the stairs into another area that looks like a chemistry laboratory with convenient workbenches for cover.
Combat Strategy: Get in cover behind the nearest table ahead of you, as Geth Troopers and Geth Hunters will come through the doors, in several waves. On higher difficulties there are at least three Geth Hunters and they will all try to close to point blank range with you, leaping right over tables to blast you with their shotguns. Apart from shooting them quickly, you can again resort to Tali's AI Hacking ability to keep them distracted - even if you don't hack the Geth Hunters themselves, they are easily distracted by other geth near them that you hack and will leave off pursuing you.
Note: The nature of the cover in this room, along with the additional waves of enemies arriving, means that if you seek cover elsewhere in the room you are likely to be exposed to deadly flanking fire. So particularly on insanity, if a Geth Hunter starts approaching too closely, it's best to flee back down the stairs to the prior room instead. The geth will follow you downstairs and you'll hopefully be able to take them out quickly enough.
Warning: The door in the room downstairs slams shut and you are now stuck in this nasty battle until it is over. If you go downstairs, understand there is not a lot of cover and the Geth Hunters and Geth Troopers will come down the stairs after you. Do as much damage as you can while you retreat down the stairs or you'll be stuck in a small room with lots of geth. After the battle the door magically opens again.
After the battle inside the chemistry lab is a crate of Refined Palladium (+2000 palladium) and med-kit with Medi-gel.
The adjacent room will have a Wall Console, which starts a testy conversation with Tali. Tali's father promised her a house on the homeworld; Tali is concerned that the research on the Alarei was her father trying to fulfill that promise. Shepard can advocate taking back the homeworld or wandering the stars for up to 4 Renegade or Paragon points. There's also a Wall Safe (+3000 credits) that can be bypassed.
Note: Save your game at this point before opening the door as the next battle will again be close quarters combat.
After going through the door, Shepard will be on the second-floor of a two-level room. Geth Troopers and Geth Hunters will be coming into the room through a door on the lower level. A few Geth Troopers will also come in through a door on the upper floor from the left.
Combat Strategy: The ramp up to the upper level makes a natural chokepoint, and Tali's Combat Drone can be used to impede geth progress up the ramp. Hacking unshielded geth also works well, and is particularly useful for distracting the deadly Geth Hunters. One thing to be careful about is hacking the Geth Hunters themselves if they are on the ramp, because while attacking the other geth they will often "back up" (toward you), leaving you in an extremely delicate position when the hack runs out. It is better in this case to hack one of the nearby lesser geth to distract the Geth Hunter.
Class Tips: Sending a Combat Drone, either Tali's or an Engineer Shepard's, inside the downstairs door at the beginning of the battle will usually stop further enemies from spawning. This section on higher difficulties can be passed by Infiltrators by immediately cloaking and rushing for the door on the lower floor. Vanguardscharging one of the geth in said area can get to the doorway. Soldiers are able to use Adrenaline Rush to race past the enemies. If you can get the cutscene to trigger through the doorway the geth will disappear immediately.
Warning: The door into the chemistry lab slams shut when you activate the door and you are now stuck in this nasty battle until it is over. There is a glitch listed below to help with the door shutting but understand that if the glitch doesn't work that the door isn't open, Shepard and the squad are now in a tiny little room and there are Geth Hunters and Geth Troopers on their way to your location. The geth will close the distance rapidly and won't go to cover until the Geth Hunters are dead. Even after the Geth Hunters are dead sometimes a Geth Trooper will enter the little room. There is almost no cover and the geth outside the little room will shred your squad unless you are very far to the right in the little room. Note: After the battle the door again magically opens to the chemistry lab.
Glitch Tip: There is also a notable glitch here that will make the room much easier on hardcore or insanity. Station one of your squad in the chemistry lab and proceed to open the door. If you feel you are overwhelmed, retreat through into the chemistry lab and take cover near a small counter near the door; some of the geth will not enter the lab, and will stand by the doorway — however, this is far from foolproof, since other geth will follow you relentlessly anyway, in which case you should prepare for close-quarters combat.
After the battle, down on the lower level is a med-kit with Medi-gel, a laptop (+1800 credits), a second laptop (+2400 credits), and another Quarian Log. Accessing the Quarian Log confirms that it was Admiral Rael'Zorah's intention to take back the homeworld.
Tali finds a recorded message for her from her father. Admiral Rael'Zorah's last words to his daughter are to order her to destroy the main geth hub and to bring the data to Admirals Xen and Gerrel. In the room to the left beside Admiral Rael'Zorah is a med-kit with Medi-gel, a Wall Safe (+1500 credits) that can be bypassed, a second Wall Safe (+2700 credits) that can be bypassed, and some power cells.
Note: Save your game at this point before opening the door at the top of the stairs as the next battle will again be close quarters combat and the door locks behind you.
Up the stairs from Admiral Rael'Zorah's body is the final battle of the mission: a Geth Prime, a Geth Hunter, and two Geth Troopers. The geth will have their backs turned towards the squad, so Shepard has the element of surprise. In between Shepard and the geth is an unbreakable glass wall. Though the geth can be seen, they cannot be targeted by powers through the glass wall.
Combat Strategy: One very effective tactic is to put your squadmates into cover behind each of the two desks at the entrance. Then, move slightly around the corner and knock down (using powers or your weapons) the shield of one of the smaller geth, and immediately hit it with Tali's AI Hacking power. Most of the geth will immediately begin fighting amongst themselves; when one slips through toward you, usually the Geth Hunter first, then you'll be able to concentrate on just that one with your entire squad.
Meanwhile you can repeat this tactic whenever the hack ends (or a hacked geth is killed) to keep the geth fighting among themselves. Eventually you will be left with just the Geth Prime, and will be able to deal with it without worrying about getting flanked or surrounded -- you can just keep falling back in circles whenever you are too hard-pressed.
Note: If you have the M-920 Cain while encountering the Geth Prime, you can fire it to the furthest wall to kill all of the geth on the bridge immediately. Shooting the M-920 Cain any closer will result in your death as well.
Before getting the evidence from the console at the back of the room, Shepard should pick a Quarian Model Ship for the model ship collection, and access a laptop (+3000 credits).
The evidence console has recordings revealing that Admiral Rael'Zorah was reactivating geth and linking them in neural networks to reach sapience in order to perform weapons test on them. However, Admiral Rael'Zorah makes it clear that Tali has no knowledge of his criminal activities. Tali begs Shepard not to reveal the evidence at trial to preserve her father's name.
Once Shepard uses the console the team automatically goes back to the Rayya.
Return to the Rayya Edit
- Use Charm or Intimidate to point to Tali's history as proof that she would never betray her people. If Shepard took the time to speak to the Admiralty Board before departing to retake the Alarei, (and thus uncovered the political debates between the admirals over war with the geth), the speech given will focus more on how Tali's trial is being abused to generate political ammunition. Either way, it will generate 30 of the appropriate morality points and the Admiralty Board will exonerate Tali, granting Shepard her loyalty.
- Lie and say no evidence was found, gaining 30 Paragon points. Tali is found guilty of treason and exiled from the Migrant Fleet. She has six hours to leave. However, Tali's loyalty is earned.
- If Shepard spoke to the Admirals about their motivations, Veetor and Kal'Reegar are present, and Shepard asked them for their help before leaving for the Alarei, Shepard can rally the crowd. The option is only available if Veetor was returned to the Fleet instead of Cerberus on Freedom's Progress and Kal'Reegar survived Haestrom. They will speak on her behalf and say Tali "did more for the fleet" than the admirals ever will. The admirals are cowed and find Tali not guilty. 30 Paragon points will be awarded. Shepard now has Tali's loyalty.
- Present the evidence of Tali's father's crimes, earning 30 Renegade points. Tali is declared innocent, but her father faces dramatic consequences. He is posthumously exiled and his name is stricken from the rolls on every ship he served. The Migrant Fleet becomes Balkanized, as the public revelation of the data brings simmering tensions to the forefront. Some ships want to use the research to make new weapons against the geth. Others want to make peace with the geth. Tali is angry at what Shepard has wrought and will not be loyal.
Note that the persuasion dialogue options are only available with a very high morality reputation, so if you have allowed Veetor or Kal'Reegar to die, you may wish to wait until you've done more to raise that reputation score before taking this mission on.
If Tali is found not guilty, Admiral Raan presents Shepard with a tech damage upgrade in thanks. With the trial concluded, Shepard may talk to Veetor, Kal'Reegar, Captain Danna, and the admirals once more.
If Tali is found not guilty, then after the trial, if Shepard talks to Admiral Han'Gerrel, he will ask what had happened on the Alarei. Shepard and Tali can confide in him about Admiral Rael'Zorah's experiments. He will be shocked to hear this, but promise to keep it a secret. Admiral Daro'Xen will also ask about what happened, but Tali will immediately reply that it's nothing that would help her.
Note: At this point Shepard will be offered the opportunity to end the mission (e.g. on Xbox360 a prominent "Press B to end mission" will be displayed), but don't leave immediately, since depending on how the trial unfolded, morality points may be earned; see the Morality Guide for details.
No matter what, upon completion, a new outfit will unlock for Tali. If you talked with the Admirals before the trial, you'll get dialogue options in which Shepard can request the Admirals move in a particular direction (war with the geth and retake the home world, or try to make peace with the geth). The admirals will reply that they'll "consider it". After the trial, Tali retains her changed name, and is listed as "Tali'Zorah vas Normandy".
Back on the Normandy, if you did not use the evidence and Legion's loyalty mission has also been completed, a confrontation between Tali and Legion will occur. Joker will inform you that Tali and Legion are having a heated discussion. Once you arrive at the AI Core, you see Tali aiming an SMG at 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 its defense that it knows the quarians were performing weapons tests on geth and that it was trying to protect its people from a possible attack, further citing Tali's willingness to be exiled for the sake of her own people as a similar action. If Tali was exiled, Legion will, instead of citing Tali's willingness to be exiled, question why Tali still protects the quarians.
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.
It is possible to salvage the loyalty of Legion if you had insufficient Paragon/Renegade to break up the initial confrontation with Tali. During the initial confrontation, tell Legion to stop its transmission, thus maintaining Tali's loyalty but losing Legion's. Then, after the conversation ends, immediately speak to Legion again. A high Renegade score will allow you to tell Legion that you "lied" about the data transmission to keep Tali happy. Legion will recognize this as "a logical decision", regaining Legion's loyalty. The required Renegade is high, but not as high as the initial conversation. If you choose this option, then both Legion and Tali will remain loyal.
- See also: Loyalty#Confrontations
After the mission, Shepard receives the following message (titled "A pleasure to meet you."):
From: Admiral Daro'Xen vas Moreh
Shepard vas Normandy,
I've been digging through the Alarei. Just wanted you to know that I did find a few things from the experiments Rael'Zorah was conducting. Had you shared them with me, humanity might have reaped the benefits. Instead, once my own experiments are complete, you and your people will watch from a distance as the quarian people reclaim not just their homeworld, but the largest synthetic army in the galaxy. Rael'Zorah's death will not have been in vain. I will complete what he started.
Admiral Daro'Xen vas Moreh
Mission Summary Edit
Tali Cleared without New Evidence: Tali’Zorah has been cleared of all charges, and her trust in Shepard ensures her loyalty on the mission. Political ramifications of quarian war efforts against geth are troubling. Likely to need quarian forces against Reapers. Cannot risk additional instability.
Tali Cleared with New Evidence: While Tali'Zorah has been cleared of all charges, she seems traumatized by the public revelation of her father's crimes. She may not be at full efficiency. Political ramifications of quarian war efforts against geth are troubling. Likely to need quarian forces against Reapers. Cannot risk additional instability.
Tali Convicted: While Tali'Zorah has been exiled, she remains in good spirits. More importantly, she now trusts Shepard and has no other ties to confuse issues of loyalty. Political ramifications of quarian war efforts against geth are troubling. Likely to need quarian forces against Reapers. Cannot risk additional instability.
- Bringing Legion along on this assignment results in some unique dialogue with the various members of the Admiralty Board, as well as quarian security personnel. Legion will also sit in the back during the trial after you have returned from the Alarei.
- In one of his lines during the conversation, Veetor will refer to Shepard with a masculine pronoun even if Shepard is female. This is most likely an oversight.
In order to reconcile the Geth-Quarian War and gain the most out of the situation you need to score at least 5 points on the following list
Mass Effect 2 Decisions
- +2 for Tali is exonerated at her trial (eg NOT exiled)
- +2 for destroyed the heretics
- +1 for resolving the Tali/Legon conflict with a renegade or paragon solution
As noted in this answer, if you did not import a game and started a new mission in ME3 you will have saved Tali, Tali will have been exiled by her people and Legion was never activated and thus the heretic mission would have have appeared. Ergo this avenue is closed if you started a new game file.
Mass Effect 3 Decisions
- +1 for Rannoch: Destroy the Geth Squadron on Rannoch (aka fighter base)
- +1 for Rannoch: Save the Admiral (not his men, the admiral)
You must also complete Legion's Mission in ME3 or the peace options will not be available. You need a high reputation to get the Paragon/Renegade options to appear.
If you rewrote the heretics in ME2 instead of destroying them, and still manage to achieve peace, you'll get more war assets but there will be less Quarians.