How to Begin
There are several requirements before you can begin this Assignment, beginning with finishing the events at Noveria’s Rift Station. Once completed, you’ll then need to complete both UNC: Listening Post Alpha and UNC: Listening Post Theta in any order. If you completed Alpha first, you’ll get the location of the Depot from the terminal in Theta. If you completed Theta first, Lieutenant Durand will mention where you can find the Depot. Regardless of how you complete the Assignments, this Assignment will begin once you enter the Depot.
Explore the Unidentified Space Facility
With the previous Assignments completed, make your way to the Gorgon system in the Argos Rho cluster and board the Unidentified Space Facility. Once on foot, head to the main room and you’ll be ambushed by a Rachni Soldier and Rachni Workers, all of which shouldn’t pose any threat so long as you don’t rush out into the open. The Soldier itself is the first threat you’ll encounter, turn to the left as you open the room to take care of.
Once the area is clear, take the time to loot this main room before proceeding to the back of the facility. At the intersection, head to the room to your right first to find a plethora of lockers to decrpyt, then leave and enter the room straight in front of you (the room on your right has nothing of value). Examine the terminal here and listen to the logs to understand the full story regarding Cerberus and the Rachni, with the third log suggesting to blow the ship.
Consider making a save here and then access the Demolition Charges, this will prime them for detonation and you’ll have 01:10 to reach the Normandy and escape the blast. This is even more difficult due to the fact that Rachni will attempt to stop you from leaving, make use of disabling Biotics and either run or quickly gun them down. You’ll have to navigate the maze again to reach the airlock and once you do, return to the Normandy to end the Assignment.