The Alphas are all rounded up without warning and stuffed into Binghamton, but that’s just the beginning. Agent Nathan Cley, who’s never had the best relationship with the team to begin with, has decided that one of them is a traitor. His tipoff? The fact that a few old scientists who worked on something called MK-Ultra, the Cold War version of the Alphas program, were all tracked down and killed by Red Flag, using information that could only have come from Alphas HQ. Cley’s individual interviews of Rosen and the team lead him nowhere, even with the help of an Alpha named Eric who happens to be a human lie detector.
So Cley’s next move is to stick them all in a room together and let them figure out. Instead, Rosen uses an apparent back injury as cover to stage a mass jailbreak. Eventually the team makes it to an abandoned warehouse, but they still have to deal with the problem of which one of them is the mole before Cley and his goons catch up to them. Rosen announces that he knows who it is, but prefers to give the culprit the chance to confess. When time runs out, Rosen fingers Cameron, and in case you ever wondered who would win a fight between Cameron and Bill, now’s when you find out. Fortunately, Cley and his team bust in before anyone gets killed, and Rosen rushes Gary out of there by stealing a government SUV. Which is bad because Rachel has just realized that Rosen isn’t Rosen at all, but an impostor. An Alpha shapeshifter, naturally. So the good news is that now we know who the mole really is.
Meanwhile, the real Rosen wakes up somewhere without his glasses and a bad haircut, but he’s still spry enough to defend himself against a hench-Alpha who was about to kill him like he killed the MK-Ultra scientists. Rosen escapes to HQ and stops Gary from deleting all the MK-Ultra files on Faux-sen’s instructions. Faux-sen almost makes his escape by turning into Gary, but Rachel’s not falling for that again. So all our Alphas are back in the DoD’s good graces, the mole’s been caught, Bill and Cameron have patched things up, Eric is probably going to join the team, and the only things left to worry about are Red Flag’s next move and how long it’s going to take Rosen’s hair to grow back.