When the imposter cook (we stand by "impasta") incarcerates you during "The Cook’s Request," you’ll find Abigail Foy’s body and her TranScribe. There’s a message from Danielle Sho asking Abby to come find her. Sadly, Abby is not going to make that meeting. But you still can.
Signal Danielle Sho in the Fitness Center
Head to the Fitness Center in Crew Quarters — you can get the code from the concierge desk computer’s email. Work your way through toward the pool. You’ll have to take out a telepath and any mind-controlled humans it’s captured when you get there.
When it’s clear, go over to the leftmost exterior window and bang on it a few times with your wrench. Danielle will float over and tell you what you already know about the cook. Killing Abby justifies the next task for this objective.
Kill the imposter cook
You get your next clue about the impasta comes during "Restore From Backup." There’s a dying-breath email you’ll find on Danielle’s computer identifying the c(r)ook as one of TranStar’s volunteers, Luka Golubkin. You can activate his tracking bracelet from the Volunteer Quarters back in the Neuromod Division. (Or you can just skip down a couple paragraphs.)
Backtrack all the way to the Neuromod Lobby, and get up to the second floor. Inside the Volunteer Quarters, you can use the Crew tab on the computer right at the front desk to pull up Luka’s record — he’s volunteer V-010655-37. He’s easy to find in the list because he’s the only one still alive.
You’ll find Luka in the Talos 1 Bridge, which you can access from the Arboretum.
When you get inside (on the other side of the load screen), head straight across the entry to the grav lifts to the escape pods. Luka is in the last pod on the left side of the room.
He’ll try to talk you into fleeing the station with him. He’s lying. The escape pod doesn’t work, and he’s got a recycler charge stuck to the wall behind him. Dispatch him in whatever way you feel he deserves to avenge Abby’s murder.