We've officially reached the halfway point of the final season of Nikita. So it's time to start putting some of these irons in the fire. "Set-Up" reveals the backstory of a major character (and it's about time!), but it doesn't have that much more to offer.

Picking up where last week's episode left off, Alex finds herself under interrogation in a CIA safe house in Mumbai. The Agency's "forensic accountant" (Rose Rollins, from NBC's short-lived Chase) is another of those 'look how tough I am' types. Nikita wants Sam to help rescue Alex, but he balks.

She then realizes Birkhoff is conspicuously absent, and he's being fairly shifty when she summons him. If that's not obvious, it definitely is when the episode cuts from that, to Amanda saying "We have a secret weapon, remember?", back to Birkhoff, who walks off after The Shop falsifies the results of Dead FBI Guy's DNA test, spoiling Nikita's plan to expose the clone army. The only thing that's missing here is a big flashing arrow pointing in his direction.

At least Ryan notices that something is hinky, and he suggests to Michael and Nikita that Birkhoff could also have been cloned. Nikita, she of the bleeding heart, calls him crazy, but reluctantly agrees to help him test his theory. When she goes to faux-confide in our favorite nerd, he confesses that "I'm not Seymour Birkhoff," and tells her about his childhood. Apparently, at 15, he faked his own death in a sailing accident to avoid being sent to military school by his father - Ronald Peller, the man that Amanda cloned at the NSA. Oh, snap.

Not wanting a repeat of the FBI Guy scenario, Nikita tells Birkhoff that they're going to save his father (Judd Nelson, yes, that guy from The Breakfast Club). The two of them locate and subdue Peller's clone, while Alex's subplot turns into an unsuccessful copy of the interrogation scenes from Zero Dark Thirty. (Eagle-eyed fans will recognize the surveillance photos as two of the promo images used from last season's "High-Value Target.")

Sonya can't seem to locate the safehouse Alex is being held in. At least Sam's had a change of heart, as he shows back up to assist her and Michael with their rescue effort. This means another awesome Michael-Sam team-up.