Since Sloane had turned in Bomani years ago, the CIA decides to tap him for more info. On the plane to Mexico City, Lauren pressures Syd to transfer to another field office. Syd is defiant. As they enter Sloane's building, he's kidnapped before their eyes; forced into a van by Sark and Bomani. Sloane, trying to prevent his torture, says he can legitimise Bomani.

Lauren apologises for threatening Syd. Later, Vaughn dreams of Sydney kissing him, then stabbing him. He wakes to find Lauren at his side.

Sloane returns to the CIA, says Bomani let him go in exchange for info — his Yakuza contacts have developed an AI computer virus that probes networks and writes itself. It can crash markets, ruin banks, paralyse the military. He wants the CIA to disable the virus, but not destroy it. If Bomani finds it destroyed, he'll kill Sloane, who suggests he's now valuable as a double-agent working for The Covenant but loyal to the CIA. Syd is dubious but Marshall's lie-detector tests verify Sloane's sincerity.

Jack, posing as a potential client, meets Simon in Paris in order to learn more about Syd's past. Javier IDs Jack and tells Simon that his daughter is Syndey Bristow, alias Julia Thorne. Simon baits Jack, who ultimately murders him when he refuses to divulge any info.

Marshall must see the code in order to render the virus harmless, so he's chosen to go with Syd. They enter the Osaka casino dressed as a cowboy and his floozy. He joins a blackjack table and cleans up, thanks to his skilful cheating. Allowing himself to be caught, he and Syd are taken to a back room. With Marshall's hands about to be cut off, Syd leaps into action. Together, they handle the thugs. Marshall breaks into the system and disables the virus just before Sark and Bomani enter the casino. They hide as Sark transfers the useless code to his server.

Mission completed, Syd visits Vaughn in the hospital, where she happens upon Lauren tenderly kissing Vaughn.