Vaughn tells Jack that he's prepared to exact revenge on Lauren. Jack tells Dixon to have Vaughn question Sark, in order to increase the psychological fear. Vaughn beats Sark bloody during the investigation. Sark gives Lauren up.

Syd calls Vaughn, and intuits that Vaughn knows Lauren's location. She asks Jack why the Sark interrogation is classified. He dodges the question, saying that Vaughn should kill Lauren to gain closure. He says that he regrets letting Irina go.

Vaughn spies on Lauren decrypting the equation in a warehouse. He photographs the longitude and latitude, then surprises her and administers a beating. About to disfigure her with hydrochloric acid, Vaughn is stabbed from behind and collapses.

Sloane sneaks into a CIA safe house and begs Nadia to tell him the location of The Sphere of Life - the vessel in which Rambaldi's consciousness is stored. She's dubious. Before he leaves, he tells her how to find him.

Syd and Jack wait for Vaughn in the hospital. Now Syd vows to kill Lauren, whether Jack, who is alarmed at her transition, helps her or not.

Lauren appears in the jail cell next to Sark. She forgives him for giving her up. He tells her that the Rambaldi info is backed up on an offsite server and gives her the password. It's not Lauren, but Syd - who removes her mask! When she determines that the equation leads to Palermo, Sicily, she leaves immediately. Vaughn tells Weiss that Katya Derevko stabbed him and that Syd is walking into a trap. Vaughn uses Weiss to create a diversion to escape the hospital.

Syd finds Katya in the Palermo site. She says she's tracking The Covenant and that she knows Lauren is present. Katya tries to shoot Syd, but Syd had secretly removed the cartridge from Katya's gun. Syd then shoots Katya. Lauren arrives but Syd misses her shot and Lauren runs.

Nadia escapes the CIA safe house to meet Sloane, who tells her that the Sphere may be compromised because The Covenant has solved the equation. She says that she purposely altered the equation - The Covenant is looking in the wrong place. She and Sloane venture off together to find the Sphere.

Syd and Lauren fight. Lauren says that Syd still doesn't know the truth about her life. Lauren is about to finish Syd off when Vaughn shoots Lauren dead. Before she dies, Lauren tells Syd that the truth is in box 1062 in the Bank of Wittenberg. Syd and Vaughn kiss.

In Wittenberg, Syd opens the safe deposit box and finds top secret documents. She cries as she peruses files documenting her life, each one bearing Jack Bristow's signature. Jack enters and says she was never supposed to have found these documents.