After completing Priority: Palaven, talk to Samantha Traynor and she will say that she was scanning Alliance comm channels and came across the message. She continues by saying that the Academy had requested evacuation and that a turian cruiser had been dispatched, normally no reason to worry. However, working with EDI, Traynor says that the signal was faked in a very similar fashion to a previous situation Shepard had encountered.
Warning: If you do not complete it before Priority: The Citadel II, it will no longer be available and considered failed.
You will be fighting infantry level Cerberus troops as well as some Atlases and Combat Engineers: many enemies are shielded. Keep this information in mind while choosing your squad. If you already have access to the bonus power Energy Drain, it is highly recommended. The Stasis power can catch even shielded enemies and with the "Bubble" evolution will remove riot shields from Guardians. Overload will be useful for pounding down shields especially on the Atlases. Consider bringing squadmates who have these abilities if you lack them yourself.
Travel to the Petra Nebula, and enter orbit at Grissom Academy.
Infiltrate Grissom Academy EditJoker will note that there are too many Cerberus ships blockading the academy for the Normandy to either sneak by or win a direct fight. Fortunately, Kahlee Sanders, apparently the headmistress of the school, comes over the communications channel and agrees to open an auxiliary loading dock where you can land. After a cutscene where Joker creates a diversion so that Shepard and the squad can take the shuttle into the school, you will land in the docking area.
Kahlee almost immediately reports that she is trapped by Cerberus operatives. There is nothing of interest in this first room, so move on to the door. Be prepared to fight immediately after opening it, because Assault Troopers are waiting on the other side. After dealing with the enemies, examine the damaged door on the right side of the room.
Inside you will find Kahlee Sanders, who has some flattering things to say about Shepard. She will inform you that there are fewer than twenty students remaining at the school, most of whom are either producing tech for the Alliance or are biotics in training for military service. If you ask about Admiral Anderson, you will find out that he and Sanders go way back to the time when he was a Spectre candidate. Proceed through the conversation however you see fit, but it will be interrupted by news of another Cerberus threat. At this point you will be booted back out into the corridor, and Kahlee will open the door on the far side for you.
Stranded Students Edit
You will immediately be greeted by the sight of Cerberus operatives dragging a student through a doorway. This is a background animation and cannot be interfered with. Do pick up the ammo on the couch, if you need it, then proceed. A Cerberus commander will come over the intercom informing students that Cerberus has taken control of the school, and they will be perfectly safe as long as they do not resist. Hop over the wall to the right to pick up the Assault Rifle Stability Damper.
Open the door and proceed through. When you round the corner on the other side of the room, you'll find two Assault Troopers talking to a biotic student who has surrounded himself with a barrier. Both troopers have their backs turned to you and are easy pickings; if you utilize your powers and weapon choices carefully, you can take them both out before they can react. Pick up the datapad (+1250 credits) on the couch at the end of the right side of the room. If you speak to the boy, Reiley Bellarmine, Shepard will tell him to play dead until the coast is clear then run back to Kahlee, and he will comply after mentioning that his sister Seanne is still inside the school. Jump over the barrier to proceed.
Classroom Battle Edit
Examine the tactical analysis review (+20xp) on the desk ahead, pick up the SMG Heat Sink in the desk in the center of the room, and the personal log (+20xp) on the desk at the right end of the room. Then head through the door on the right and the next door, witness a fleeing student being gunned down, then take cover and wait for Cerberus operatives to come through two doors on the far end of the room. You can take down the Shield Generator to remove their primary means of cover. Tip: Shoot the generator when enemies are standing near it to create a damaging explosion.
There will be one or two Assault Troopers, but the bulk of this unit is made up of Centurions with full shields, so plan accordingly. Go into the hallway on the left to pick up the M-22 Eviscerator. Head back across the room with the shields, and go on the right side of the couches to pick up the M-96 Mattock. Go right to open the locker (+1250 credits), then return back up that hall to pick up the Mnemonic Visor. Continue on to talk to Seanne Bellarmine; speak to her quickly, because if you stand around too long she will keel over and die. Return back down the right side hallway toward the accessible door.
Orion Hall Edit
As you approach the door, Kahlee will come through to tell you that she just received an emergency message from the students in Orion Hall. Before entering, take out the generator that is feeding power to the Cerberus logo above you. Kahlee will come over the PA and announce that help is here. You will enter to see the biotic students defending themselves from Assault Troopers. If Jack survived the Suicide Mission, she will be among them and will greet Shepard; otherwise, Ensign Jason Prangley will step up and take charge. Note: Jack will not be present if an ME2 save was not imported.
In any case, Shepard informs them they are with the Alliance just before an Atlas breaks into the room. The students wisely decide to let Shepard handle it and retreat behind a biotic barrier; you must defeat the enemies before the barrier wears down. The Atlas is dangerous if you get in its line of fire, but it is slow and will not take any more interest in Shepard than in your squadmates. The Assault Troopers and Centurions in the middle of the room are much harder to avoid, because they are fast and may drift dangerously around your flanks, though they often get distracted attacking the students. Tip: On higher difficulty levels you will therefore want to concentrate on lowering the population of troopers before taking on the Atlas, particularly because if you get distracted halfway through the Atlas it can get its shields back up effectively erasing your progress. Luckily, at the beginning of the encounter, the troopers will be huddled together, so using a few Power Combos will make quick work of them.
After the battle if Jack is present, she will berate Shepard for their previous involvement with Cerberus. If you romanced Jack, she will punch the Commander for leaving her instead, after which she will passionately kiss him. If Jack is not present the students will say that their CO was killed, leaving Ensign Jason Prangley in charge. In addition, without the benefit of Jack as their teacher, a student, Rodriguez, will ask you if you ever forget the first time you kill someone, giving you extra Paragon or Renegade points. The kids will now need a few minutes to recharge, since they've been constantly fending off Cerberus operatives for hours. You can speak to Jack for some exposition if she is present. She will make references to the mission on the Collector Base, noting how she held the biotic field together against the swarms if you selected her for that task during the Suicide Mission.
Immediately after these conversations, Cortez will come over the communications channel to say that it's too dangerous for him to keep the shuttle docked. Shepard will order him to get back to the Normandy, then Kahlee will come through with some ideas about alternate ways out of the facility. Relative to where you came in, on the near right you will find a data log (+20 XP) listing Prangley as a high priority capture target and the Cerberus camera control. In the far back right you will find a med kit (+100 XP). In the balcony room with the students, you will find the Assault Rifle Precision Scope in the back of the room, and a datapad (+1875 credits) in the front of the room. Along the back wall, use the door override controls to open the door below.
Tip: Now is a good time to check if you have leveled up, if you have not done so up to this point.
Head back downstairs and to the door into the Atrium, located under the room you just left. The students will suggest that they follow a different route to attack Cerberus from above. Respond however you like, then get treated to the Cerberus announcer telling the students that the Alliance soldiers are going to get them killed and that they should just surrender. Again, respond how you will, then move forward through the door.
Atrium, Part 1 Edit
The next room will contain the hardest fight yet. There will be an Atlas accompanied by countless Centurions, Guardians, and Combat Engineers. Just when you think that you're making headway, more waves of them will appear, so prepare yourself for a long fight. Fortunately, biotics students will help you with any enemies that stay on the ramp or high enough up on the stairs, but don't depend on them to do too much of the work for you. James is a very good choice for this fight because he has the only disable (Carnage) that isn't blocked by shielding or riot shields, which every enemy in this fight has. Liara is even better if her Stasis has the "Bubble" upgrade which will not only disable anything but the Atlas, shields or no, it will also instantly freeze Guardians and remove their shields. Garrus can strip shielding from enemies at long range with Overload, and if equipped with his sniper rifle will do significant damage to enemies.
It might be a good idea to just open the door and stand there, letting the first wave of Centurions and Guardians come to you. In this way, you can take out several enemies before the bulk of them engage you. It is best not to get trapped in the corridor with only the sides of the door for cover, so move out into the room once you take down the immediate wave of enemies that rush the door, but be aware that it will close and lock behind you.
After venturing into the room, you'll have to move around from cover to cover in order to stay safe, because there are a lot of enemies and they will all try to flank you. Stay out of the line of fire of any Turrets set up by the Combat Engineers and move around picking off enemies (Infiltrators and Engineers should Sabotage the turrets to cause maximum carnage). There are Shield Pylons that you might take out to give yourself an easier time, but it is not necessary, so don't put yourself at risk to do it.
Insanity Tip: The courtyard is divided into two by a huge wall, and the Atlas is on the other side of that wall and cannot cross. This leads to a second possible strategy, and the safest one for higher difficulty levels: if you turn right from the door you emerged from, you can head up a ramp to find a Shield Pylon right next to the dividing wall. This takes the Atlas out of the fight, and you can also defend from the high ground quite effectively. The only thing to be wary of is that two Guardians will spawn at that high ground, so shoot the shield generator in the upper corner before they appear, and then a Stasis Bubble will usually catch both of them for easy pickings. Whoever is leading the biotic students accompanying you will shout "Up here!" at the moment they spawn. If you live through the Guardians, the rest of the fight should be fairly straightforward. Finally, take the Atlas out once all the troops are down, because next you're going to its half of the courtyard.
After all of the enemies are down, replenish your ammo and move through the door on the lower level. Pick up the mission brief (+20xp) on the chairs on the left and the med kit (+100xp) on the right and any additional ammo you need. Then use the computer on the left before the door (+3750 credits). If you had not leveled up earlier, check and see if you have now before moving through the door.
Atrium, Part 2 Edit
This is the other side of the Atrium. There are one or two Centurions and Guardians and several Combat Engineers, but the bulk of the enemy force is made up of Assault Troopers. The biotics students will continue to help you, so head into cover and pick them off one by one. When planning your cover, be aware that enemies will be arriving over the wall and landing on the level above you. During the battle, one of the biotic squad, Ensign Rodriguez, will snag a round, but don't let the shouts for medigel distract you. She'll be fine anyhow. In the Wii U version of the game, the exclusive M-597 Ladon heavy weapon can be found in this room, which will make this section much easier.
Insanity Tip: After opening the door and thus triggering new wave of enemies to appear, one can return to the first side of the room and no enemies will follow. This way enemies can be taken out relatively safely. Note however that there may be a few enemies and Turrets that might not be visible from the first side. So once you think all enemies are down and proceed to the second room (for the second time), be careful!
That's an Impressive Barrier, Octavia Edit
There is nothing of interest in the room, so after the enemies are down move through the door on the other side of the space and replenish your ammo, then head through the next door. Move up and take cover, because to your left two of the tech students are fending off two Assault Troopers with a barrier/shield combo device. Listen, if you like, to a short conversation between Octavia and the troopers before engaging them. Then, take out the troopers, then go back towards the right to access a computer terminal for 4375 credits.
You can now speak to Octavia, who is understandably distrustful of Shepard. You can either contact Kahlee to convince her that you're a friend, a squadmate can disable the shield, or you can shoot through the shield. However, if Overlord was completed in Mass Effect 2 and you followed the Paragon route at the end, David Archer will vouch for you, and unlock the door behind them, which contains another M-96 Mattock or M-22 Eviscerator and a Sniper Rifle Piercing Mod. David has some extra dialogue should you bring Garrus or EDI with you. If not, make your choice, then head through the door and collect the Biotic Amp Schematics from the terminal on the right. Proceed to the next room and retrieve the Serrice Council Chestplate from the couch on the left.
And Now a Word From This Atlas Edit
The next room has an Atlas and a Combat Engineer, but the Atlas does not have a driver. Pick up the med kit (+100xp) on the couch on your right, and access the engineer's data log (+20xp) to find out that Rodriguez, the biotic who got shot during the last major fight, is a high priority target for Cerberus indoctrination. Climb into the Atlas and head up the stairs to the docking area. There is an SMG Magazine Upgrade on the left bench of the entrance you came in, you can pick it up after the fighting.
There will be many waves of Assault Troopers, Guardians, and Centurions, but you should be able to handle all of them from the Atlas. Just be sure to be near cover if your armor starts to get dangerously low, because you will want to evacuate, but even on Insanity level the Atlas is pretty sturdy. There will be several waves of ground troops emerging from various points around the room. After almost all of the ground troops are down, an enemy Atlas will come through the door where you entered. When someone shouts that "the shuttles are almost ready" you'll know the Atlas will appear soon. Atlas Tip: The secondary missile attack of the Atlas is mainly useful for groups of enemies who aren't in cover; its cooldown period isn't surfaced very intuitively, so just remember it is available to fire approximately every five shots from your main gun.
Before you leave the academy, ensure you have picked up the SMG Magazine Upgrade. To retrieve it, head toward the stairs the enemy Atlas came from, and inspect the seats to the right of it for the SMG Upgrade.
Escape to the Shuttles Edit
Head through the doors to the shuttles. A cutscene will play showing the students and your squad rushing for the shuttle, where it is discovered that Rodriguez has fallen behind and is being pursued by Cerberus operatives. Shepard will attempt to get to her through the glass, but whoever is in charge of the biotics squad will smash the glass first and pick her up. If it's Jack, everyone gets out. If it's Prangley, he's shot and killed just before he makes it.
Once inside the shuttle, Kahlee Sanders will request that Shepard rethink having the students play a military role, especially if Jack isn't around and their instructor and their student leader are both dead. Make your choice, then you will automatically be returned to the Normandy for a video conference with Anderson, who will discuss the war and ask about Kahlee. You will then receive 12,500 credits in Alliance funding.
The following log appears only if Jack survived the Suicide Mission.
If Javik is part of your crew, you will find him in the walkway beneath engineering following this mission. He will comment about Jack's previous tenure in this room.
After the evacuation, Kahlee will send an e-mail to the Commander, forwarded by Admiral Hackett.
War Assets Edit
By choosing "We'll use them as support.", they get rolled in with the Alliance 103rd Marine Division. This adds 50 war assets to the 103rd and earns you Paragon points.
By choosing "They're ready for battle.", they will become a Biotic Company in the Alliance. This adds 75 war assets and gets you Renegade points.
In the Extended Cut, Jack's slide in the epilogue will be determined based on this choice. If sent to support roles, Jack will be shown back with her class. If sent to combat roles, Jack is shown mourning at their gravesite, suggesting that they took heavy casualties on the front lines.
Citadel Spectre Terminal Edit
You can authorize stationing and housing for the Grissom Academy students on the Citadel from the Spectre Terminal. This upgrades the value of the Citadel Defense Force war asset, which mentions that some of those students are taking over repetitive tasks which cannot be handled by VIs.
If the mission is not completed before Priority: The Citadel II, it will expire. Aside from the obvious consequences of losing experience points, credits, the large number of weapon upgrades mentioned above, and the possibility of rekindling a romance with Jack if one was begun in Mass Effect 2, this will also have plot consequences: during Priority: Cerberus Headquarters, Shepard will encounter Jack, who was captured by Cerberus and was turned into a Phantom. Shepard will be forced to fight and kill Jack. Also, if you completed Overlord and sent David Archer to the Grissom Academy, you will meet Dr. Gavin Archer during the mission, Arrae: Ex-Cerberus Scientists, where, depending on what you say, he may or may not kill himself for not getting the chance to apologize for his injustice.