A cunning new adversary's carefully crafted plans force Mac to make an impossible choice: save the life of a friend, or save hundreds of innocent lives; Mac receives new information that will drive a wedge between him ...
Mac, Dalton, and Cage pursue terrorists who have obtained a canister of deadly nerve gas; Bozer has been paired with Leanna for interrogation resistance training; Riley considers accepting her estranged father's invitation to dinner.
Mac helps a group of researchers trapped in the Arctic Ocean on a research vessel; Jack kidnaps Elwood, only to end up helping him deal with his past; Bozer and Leanna find themselves handcuffed together in a new test.
The partying son of a Serbian war criminal takes his new bride to an exclusive French chateau for their honeymoon, and Matty assigns Leanna to work with Bozer, Mac, and Riley to go undercover and find out where the father is. Meanwhile, Jack convinces Elwood and Jill to help him break into Matty's house to find out what she's hiding from Mac.