Michael collapses, and must go to the hospital; Sucre steps on a landmine; Mahone meets with Scylla's designer; and Trishanne has a surprising secret.

Senator Conrad Dallow pays Don Self a visit at his office. Bellick's body was found; fortunately, it was transferred to Homeland. He wants Michael and the others transferred to the Supermax in Texas; too many people are asking questions. If they can finish the job right away, great; but either way they're going to end up at that Supermax. The deal for their freedom was for them to take down the Company in a week, and it's been more than a week. Don bears the bad news to the gang; Sucre is outraged that Bellick's body has not been returned to his family. Self says he needs results. Michael says he needs the rest of the pages from the bird book. They get the pages from Gretchen, who tells them that Scylla is being moved to a bunker in Pennsylvania by tomorrow. Michael's suspicious as to how Gretchen knows that. As Sucre puts off making his promised call to Bellick's mother, Michael examines the pages: a floor plan with symbols and letters. The letters spell out the name "David Baker," and we see a silhouette of the mysterious Mr. Baker examining a detailed model of a city.

Trishanne has used Gretchen's fingerprints to get a profile of Gretchen from a friend of hers who works with the California Highway Patrol. There's very little information, and no mention of any connection to Scylla, Chinese mobsters, or our gang; including, says Trishanne, Whistler. T-Bag becomes suspicious: How did she know the name "Whistler"? She says she heard Michael mention him, but T-Bag doesn't believe her.

Sara searches online, and finds a David Allen Baker who advises the city planning commission, and won an award for designing low-income housing. Michael hides a flash of pain as everyone studies the map, but as the meeting breaks up Michael collapses, unconscious. He recovers moments later, but is dazed. Sara takes him to the hospital as Mahone volunteers to go to David Baker's address. T-Bag asks White about Trishanne; she was hired as a temp a week before T-Bag arrived. He wants to see her application. White asks T-Bag to step in for Andy Blauner, and host an intro for new employees. Gretchen arrives, and warns T-Bag that Scylla is being moved. The plan is to wait and see how Michael does; either he'll find Scylla, and they'll take it and sell it to Feng... or he'll be caught by the Company, and she and T-Bag at least won't get taken down with him. Linc and Sucre arrive; with Michael incapacitated and Bellick dead, they need T-Bag's help.

As Sara checks Michael into the hospital with a fake ID, Pad Man meets with Howard Scuderi, who is worried about losing access to Scylla at this critical stage. Pad Man says the plates are ready to print as much currency as they need, but Lisa says moving Scylla is tricky, and taking longer than they thought. To move things along, Pad Man has his aide call David Baker. Mahone arrives at Baker's home, and says he's with the Company and needs information about Scylla's design. Baker says it was too long ago. Mahone chats to him about his model city: if built, it'd be entirely self-sustaining, in harmony with itself and the world. They talk about Scylla again, and Baker realizes that Mahone isn't Company.

As Linc and Sucre return to the pipe where Bellick died, Sucre talks about what happened at Sona. T-Bag went crazy and lit Sona on fire, telling everyone to run: "they can't shoot us all." Sucre was getting trampled, but Bellick pulled him up, and saved his life. They crawl through the pipe to the Company side of the tunnel. Down some steps they find a massive concrete wall in their way. The wall has to come down. Then a beep is heard: Sucre has stepped on a mine. Linc runs back to T-Bag's office, and grabs Gretchen. T-Bag gives his intro speech to the new employees, and makes an unexpectedly emotional speech about Bellick. Gretchen claims no knowledge of the mine, and doesn't know how to disarm it without Sucre moving (and triggering it). Linc calls Michael, but as the phone rings the doctor who was tending to Michael (Dr. Malden) walks towards him and Sara with two cops in tow. As the nurse talks to the cops, Dr. Malden tells Michael he knows who he is, but he's not turning him in: he's just worried about Michael's condition, and the CAT-scan results are going to take another couple of hours. Michael won't agree to be admitted. As he leads Sara away, Sara implores Dr. Malden to call her.

Trishanne meets with Don at his office: she's an agent, and has been working for him all along. She tells him that T-Bag is on to her. He offers to reassign her, but she refuses: they're going to bring the Company down together. As Mahone tries to persuade Baker to help him, a pair of Company men arrive at the door. Baker's wife Elaine (who was listening to the conversation) tries to stall them, but they push past her. Mahone's phone rings; it's Linc looking for help with the mine, but the cell phone signal is weak. Mahone goes outside, and then sees the Company goons through the window. He hangs up, and ducks back into the house, again begging Baker to help before it's too late. He won't talk. Mahone is forced to flee before the Company men discover him there, begging Baker not to help them as he goes. Baker surrenders himself to the Company men as Elaine helps Mahone escape while pressing something into his hand: the legend to the blueprint.

With no other choice, Linc and Sucre allow Gretchen to try to disarm the mine. Mahone joins Michael and Sara at the warehouse. The legend tells them that the land mines are an alarm that must be deactivated manually. Any conventional attempt to dismantle it — like Gretchen is about to do — will trip the alarm. Mahone takes off for the tunnel. Michael tries to call Linc, but goes right to voicemail. Mahone arrives just in time, screaming for them to stop. He then uses the legend to find the manual override. Sucre is finally able to step off the mine. Linc asks what's on the other side of the wall: "Scylla," says Mahone.

Everybody's back at the warehouse. Don arrives; he's on his way to the airfield to send Bellick's body home. He allows the gang a moment with the body to say goodbye. Michael takes a badge found by Bellick's cot, and puts it on his chest. Sucre steels himself, and then calls Bellick's mother to give her the news, as he had sworn to do. White brings T-Bag Trishanne's application. T-Bag calls the number for the reference… and recognizes Don's voice on the other end. T-Bag hangs up, enraged.

At the warehouse, Michael has decoded the floor plan. Beyond the alarm, there's a wall fortified with steel fiber. There are no cameras — the Company doesn't want any visual evidence of Scylla — but there are sensors and microphones in the floor that will alert Company security to the presence of any breathing human weighing more than two pounds. They have to get over the wall, and then cross the floor silently… without touching it. Sara gets a call from Dr. Malden. Michael needs surgery immediately... or he could die.