Jack contacts a mysterious woman with ties to Irina to help him free Sydney and Vaughn, who have been captured and face a North Korean firing squad. But Jack is faced with a curious conundrum when the woman tells him that she will not put the rescue plan in motion until he fulfills a favor - assassinate Sloane.

With the aid of Katya Derevko and CIA imprisoned security systems designer Toni Cummings, Sydney and Vaughn attempt to track down Sloane and Nadia. But Lauren and Sark are also in hot pursuit of them in order to uncover the secrets of Rambaldi. Meanwhile, Vaughn's obsession with tracking down Lauren is beginning to consume him, Sydney and Vaughn turn the tables on an old foe, and Katya expresses her attraction to Jack.

Lauren stages a stunning betrayal to steal classified materials from the CIA. Meanwhile, Vaughn comes face to face with his darkest demons in pursuit of his wife; Nadia must decide whether or not she can trust her father, Sloane, in the pursuit of Rambaldi's most priceless artifact; and Sydney receives a shattering revelation that will make her question everything - and everyone - she thought she could trust.

In an attempt to talk to Sydney, Katya Derevko deliberately poisons herself and is temporally taken out from her cell. Once Nadia tells her sister about this, Sydney visits her aunt to tell her to stay away from Nadia. However, Katya unsettles Sydney by telling her that someone framed her mother as a means of getting her killed. Sydney sets off in search of the truth behind this story. Meanwhile, Vaughn becomes a rogue agent by getting involved with the people who might know his father's whereabouts. In the end, he and Sydney find out that the man behind these two plots is no other than A. Sloane. However, things are not exactly as they seem to be.

After a tactical group infiltrates the DSR and steals Rambaldi artifacts, CIA director Hayden Chase discovers that the alarms at the DSR were disabled from Nadia's computer, allowing the raid to happen, and shows up at the apartment to question her. Soon Sloane and Jack arrive and suspect that Sophia, who had access to the computer while she was living with Syd and Nadia, is Elena Derevko. They follow her trail to a dead Rambaldi follower, a stunning betrayal, and a presumed dead family member...