Tom visits Rachel in her apartment. She consoles him in his sadness and he leans in to kiss her. When Rachel goes in the kitchen, Tom leaves. Later, Rachel is abducted by Sark. Around the same time, Marshal is abducted from his home and is brought to Sloane's hideout. With Peyton, Sloane asks Marshall to hack into the government system and locate an underground cavern by accessing the federal ground-penetrating satellite. When Marshal refuses, Peyton tortures him.

Syd and Jack visit Carrie, Marshall's wife, who called them for support in finding Marshal. When Syd reveals to her that Marshal is still working for the CIA, Carrie volunteers to help and provide technical support in Marshal's absence. As soon as Carrie arrives in the APO office, she cracks the password for Marshal's program to track Prophet Five members.

Later, Sloane confronts Sydney in the parking lot as she was carrying Isabelle. Sloane tells her to talk to Marshal, who is determined to not give in. Syd then tells Marshall to do what Sloane says and asks what he wants to tell Carrie. He asks Syd to tell Carrie to finish reading the book "The Littlest Fish" to their son.

Rachel arrives in the same room as Marshal is in. Marshal tells her that he needs her help in doing Sloane's bidding. To ease Rachel's confusion, Marshall tells her that he had spoken to Sydney. Marshal suggests that they leapfrog across the network so they would not get caught in their hacks. With an understanding that Marshal actually wants to get caught, they begin to work on their laptop. Later, Rachel locates the cave that Sloane wanted in central Italy.

Vaughn relays Marshal's message to Carrie, where Carrie figures out that the lead character in "The Littlest Fish" is named Noah. With Sloane's motives, she concludes that Marshal must be referring to NOAA the National Oceanic and Atmospheric Administration-something that Marshal must be hacking currently. Going with this possible lead, Carrie sets up trip wires to monitor government hacks and pinpoint Marshal's location. Later she finds Marshall triggering network security protocols. She narrows his location down to Ixtapa and Jack sends a rescue team.

In the basement, Rachel picks her handcuffs with an under wire and with Marshal, they escape the guard who was sent to kill them. Followed by other guards, they run through a corridor in time to be rescued by the APO Team who just arrived.

At the APO office, Carrie reports to Jack that based on Marshal's tracker, the Prophet Five members seem to be gathering in Zurich. Jack assumes that Sloane must be presenting the information that Marshall and Rachel uncovered -he then assembles a team to strike. Retrieving information at Sloane's safe house, Rachel mentions that Sloane is going to Umbria. Sydney realises that he must be going to Mount Subasio.

Climbing the snow-covered mountains, Vaughn propels Sydney down to the icy underground cavern, where she finds Sloane with the Rambaldi amulet. When Syd holds him at gunpoint, Sloane says that a shot will trigger a cave in. Meanwhile, in Los Angeles, Sark sets a timer for a planted bomb.

At the APO office, Tom reports that based on the files in Sloane's hideout, bombs are being planted around the APO office through the subway system. Jack tells them to clear the office while Tom and Dixon sweeps the tunnels for the bomb. Marshal and Rachel are tasked to evacuate civilians. Later, Tom finds the bomb and reports that it can't be dismantled because of the fail-safe components. He suggests freezing the timer with liquid nitro to extend the countdown.

Peyton goes to Zurich and meets Prophet Five members. Standing in the middle of the room and expected to present the amulet, Peyton opens the briefcase and pulls out two semi-automatic weapons. She kills all the members of Prophet Five and their bodyguards who arrived shortly.

When the last of the civilians were cleared out of the tunnel, Jack tells Tom to get out of the train and run to safety. Instead, Tom asked to be patched to Rachel. He tells Rachel that if they had more time, he would have asked her out. Sensing that Tom is giving up his life for this cause, Rachel tearfully replies that she would have said yes. At that moment, the building implodes.

Sloane holds the amulet against the light. He tells Sydney she is not allowed to see it and he shoots the icy ground she is standing on. Syd falls through and is rendered unconscious.