Arrae: Ex-Cerberus Scientists

A group of top-level scientists have cut ties with Cerberus and are fleeing their former employer. Rescue the scientists before Cerberus finds them.

Acquisition
This mission is acquired from Specialist Traynor after the Cerberus assault on the Citadel. It is acquired through dialogue aboard the Normandy.

Landing
The mission begins with a landing on an area that is already under assault by Cerberus forces. Lt. Jacob Taylor, from Mass Effect 2, is injured in the firefight; if Jacob died during the Collector Base assault, a stand-in character named Dr. Webber will be injured instead. After Shepard clears the initial pad area a conversation ensues. Jacob will vouch for Shepard, but in his absence, the refugee leader, Dr. Brynn Cole, will be mistrustful due to Shepard's past ties with Cerberus, forcing you to engage three more Assault Troopers before she'll let you in.

At the start, you can talk to a grieving doctor for some paragon points. You may also talk to Jacob Taylor on entry as well, and investigate into what's happening. (Hilariously, if you have EDI on your squad, after the conversation with Jacob Taylor she will make a comment saying, "I don't think he recognized me. It might be my chance to surprise him!" Referring to the fact that Jacob Taylor hasn't seen her new mechanical body as his presence was not on the ship at the time.) Dr. Gavin Archer may be present at the top of the first flight of stairs with a datapad with 2,500 credits, and another datapad with some insight into some of the research being done. Through the door is an Assault Rifle Magazine Upgrade and a Weapon Bench. Up the stairs and through another door is a medical station. Upon talking to Dr. Cole, Shepard will also be alarmed by the discovery that some of the scientists brought their wives children with them. Jacob (or Dr. Webber if Jacob Taylor didn't survive the suicide mission.) will inform Dr. Cole that the installation's roof-mounted anti-aircraft guns are offline. On the top floor is a datapad with 2,500 credits, a microscope that triggers a comment from Shepard about a poison designed for turians (Which then triggers the quest Citadel: Cerberus Turian Poison, see the Acquisition of the quest article for clarification on that subject.) ,another datapad about the work they were conducting, and a Shotgun High Caliber Barrel mod behind a crate near the door to the next area. You can also talk to Dr. Brynn and listen to the others for more information. In the medbay you can find a datapad with 1,250 credits, another datapad from Jacob about the AA guns, Kassa Fabrications Greaves, a medical station on the wall, and you can talk to Jacob if he's present. (Amusingly, if he's not, even the bed he is sitting on will be gone.)

AA Guns
Shepard is tasked with restarting the AA emplacements. To do this, head out through the door and up the ladder. Be sure to grab the M-6 Carnifex on the pipe to the left if you don't have it already. When you come around the corner, there are guards facing the wrong way, but they're standing near a Shield Pylon, so if you want an ambush you'll need to snipe the Pylon, hit both guards with a Chain Overload/Energy Drain, and then finally start shooting. It might be easier to just do a stand-up fight. Either way, continue up the raised platform to find another Combat Engineer guarding the satellite control area. Back-up will jump down to join him, and if you can place a Singularity under them, you'll win without breaking a sweat. Pick up the SMG High Caliber Barrel behind the crates on the left right after the drop down. Once you restore the controls, Jacob or Brynn will tell you that the AA guns still need to be activated. Next to the controls, a Med-kit and a Datapad worth 2,500 credits can be found.

Cerberus forces drop onto the raised platform you just vacated. Clear them out and ascend. In the distance, by the right AA gun, will be a turret manned by an unshielded gunner as well as typical assault forces. Before climbing the tower, there is a medi-kit in the center past the corrugated surface you climb up to in three steps under a curved metal pipe, as well as a Sniper Rifle Piercing Mod that can be found behind the large containers near the ladder to the right tower. This ladder is broken, so make your way up the left tower. Activate the AA gun and move across the crosswalk to the adjoining platform.

On the second AA tower is a Datapad containing 3,750 credits, a Med-kit below the datapad and a turret, down the ladder is a Shotgun Spare Ammo mod. Climb back up and activate the second AA gun to discover it requires repairs. Assign the squad member of your choice and head to the turret. On the other AA tower and on the platform below Cerberus shuttles will deploy troops including the highly evasive Phantoms; use the turret to obliterate the opposition. Once all enemies are dead return to the AA gun and activate it.

Evacuation
Once you return, Dr. Cole discuss the situation with you and ask if the scientists should go now or wait. This is not a tactical decision; she is giving you a chance to prep before the final battle. There's really no reason not to just go immediately, especially as all the doors leading in and out of the room are locked, making it difficult to go back for any loot you forgot. If you choose to delay there are a 3 datapads (2 with info, 1 with 2500 credits) and a shotgun mod in the room you can pickup.

Once evacuation begins, Cerberus troops land and you have to fight them. Dispatch the two troops in the upper area and head down below to dispatch the three troops on the ramp.

When the hangar doors open there are several troops to battle, as you move forward Cerberus shuttles drop more troops on the raised platforms. Press the advantage and see the second scientist shuttle off. The third shuttle is piloted by Jacob/Brynn and is tasked with picking up Shepard. This part of the battle is only difficult because of the Atlas; destroy the Atlas and the end cut-scene ensues. (Again, Dr. Webber serves as the Jacob replacement, making a darn good showing of himself in the firefight.)

Results
Upon completion of this mission, you will gain 12,500 credits and adds Ex-Cerberus Scientists and Dr. Brynn Cole to your War Assets. If Jacob is present, he will be recruited as a War Asset as well, and can later be interacted with at Huerta Memorial Hospital. Finally, you can also gain Dr. Gavin Archer as a war asset provided you satisfied the following conditions:
 * Completed the Overlord DLC mission in Mass Effect 2.
 * Successfully rescued the Grissom Academy students before this mission.

Trivia

 * The evacuation cinematic bears a strong resemblance to the evacuation scene in Star Wars: The Empire Strikes Back - In both scenes, ground-to-air defenses are used to clear a way for the escape craft, and the evacuation is also cut short by the arrival of enemy troops. Some of the dialogue options are almost direct quotes from that sequence.
 * If Kaidan Alenko has been recruited to the Normandy then after completing this mission a conversation will be available where he ponders about the fact that there are good people in Cerberus and asks Shepard about the Illusive Man in an attempt to understand him.