While Linc, Sucre, Sara, and Roland follow a Scylla cardholder to Vegas, the others go after T-Bag; and Don confronts Pad Man.

Gretchen forces T-Bag at knifepoint to spill whatever he knows about Scylla; all T-Bag knows is that — thanks to the bird book and his infiltration of Whistler's alias — he's the key. Cardholder Howard Scuderi has chartered a flight to Vegas just as they were about to make their move. Michael convinces a reluctant Don to let them tail him and get the card right away, rather than wait a week for his return. If they're not back by midnight, however, they're going to jail. Don asks Mahone's advice on how to shake off Wyatt; if Don's killed, they all go to jail. Mahone replies that he was outdone by Michael (when they were adversaries) because Michael didn't run: he got aggressive. Meanwhile, Pad Man orders Wyatt to kill Don and make it look like an accident.

Bellick gets a call from Trishanne: she wants $2000 for info on T-Bag's whereabouts. Mahone, Bellick, and Michael decide to stay behind to go after T-Bag while the rest go to Vegas. They meet with Trishanne… but it's a setup. T-Bag pulls a gun on them, and has a surprised and terrified Trishanne handcuff them. They're bundled into a van, but Mahone manages to escape. At T-Bag's apartment Michael, Bellick, and Trishanne are handcuffed. T-Bag wants to kill Michael very badly, but he needs Michael's help to interpret the symbols in the bird book. He orders Michael to write down everything he knows about Scylla. Michael notices the mention of GATE in the book, and GATE on a box in T-Bag's room. He asks T-Bag what GATE is. T-Bag thinks Michael is stalling. He pulls a gun on Trishanne, threatening to kill her if he doesn't start writing. Michael buckles, and begins to explain that the pages in the book are a blueprint. Then T-Bag gets a phone call… from Gretchen, who has been watching from the bedroom so that Michael won't know she's involved. She's noticed Bellick's ankle monitor. Federal agents could show up any minute; and indeed, Mahone has gotten a tracker from Don and is heading in their direction. Gretchen tells T-Bag to get him the serial numbers of the monitors.

In Vegas the rest of the gang scours a casino where Scuderi has a $400,000 credit line and a comp-ed suite. Sara's concerned that Michael's not returning her calls. Linc tells Sara that their mother had a tumor since childhood that caused nosebleeds; a little bit in her teens, and then they returned in her 30s. She got migraines, and eventually died of an aneurysm. Michael has the same tumor, and got a nosebleed the other day. Sara's floored, but a phone call from Sucre interrupts: he's found Scuderi.

Mahone reaches T-Bag's apartment… and finds the ankle monitors and an empty apartment. As Gretchen goes to GATE to talk to Andy Blauner, we find that T-Bag has taken the others to Trishanne's place. Michael has torn out the pages of the bird book, and assembled them into the blueprint: it's the building that Scylla is in. There's a tunnel that'll get them in, but part of the blueprint is missing – where's page three? T-Bag says that he ate it. Michael says he's guessing that Scylla is on the penthouse level, and explains that Scylla is the Company's black book. T-Bag forces Michael to say that he's in this for the money, just like him, and then smirks that he and Michael "ain't so different after all." Mahone finds an origami bird at T-Bag's apartment. Wyatt arrives at Don's apartment only to find it abandoned and empty. He calls Pad Man, who says to notify their people in the Bureau and the LAPD to keep a lookout for him. Pad Man's aide interrupts: Don Self is there to see him.

In Vegas, Scuderi's on a losing streak. Linc sits down next to him. In another room Roland's monitor for the device goes wild, downloading tons of information and filling up almost immediately. He texts Linc to pull out, so Linc has Sucre tail Scuderi. Roland, Sara, and Linc examine the device; it filled up with data from the slots, so there's no room for the card information. Sara and Linc accuse Roland of doing this deliberately, to find out when the slots pay out. Sara says they need to get Scuderi alone. Sucre reports that Scuderi is lounging by the pool in a bathing suit; there's no way he's got the card on him. Linc realizes that the card is in his room. T-Bag meets Gretchen behind Trishanne's apartment; in her trunk is Blauner, bound and gagged. T-Bag says Michael needs to see the GATE offices or he can't make any further headway.

Don confronts Pad Man with copies of all the files he has on the Company. Don's sent five more copies to lawyers across the country, along with a sealed letter explaining Pad Man's involvement. The letter will be opened if Don turns up dead or missing. Pad Man says that this is ancient information that he personally had nothing to do with; the trails won't lead to him. Don says it doesn't matter; if an agent investigating Pad Man is found dead, he'll find himself under so much surveillance that the Company will be permanently hobbled. Then he tells Pad Man to back off of him. Pad Man smiles, impressed, and offers Don a job with the Company. Don refuses, and leaves, victorious for now. Gretchen forces Blauner to sign a letter of resignation from GATE. As T-Bag gloats, and a horrified Trishanne looks on, Gretchen garrotes him. T-Bag then takes Michael to GATE. In the anteroom off of T-Bag's office, Michael pulls up the flooring, and finds a rusty hatch. Dust flies as the hatch is opened, revealing a ladder down into darkness.

Sara, in a bikini and a wig, tries to get Scuderi to take her to his room, claiming to be on a scavenger hunt for a photograph in a "whale's" suite. He refuses. As he leaves, the bartender tells her not to take it personally: she's not his type… Scuderi hit on him a few minutes ago. A reluctant Sucre is pressed into service to seduce Scuderi just long enough to get into his room with the device. Sucre pretends to have lost all his money at the tables. Scuderi offers him a thousand dollars to come up to his room. Once there Scuderi reveals that in Vietnam he got his groin permanently damaged in an explosion. He has no sexual function. He's brought Sucre upstairs to have sex with his stunning wife. Down the hatch there's a caged room in the corner… and Mahone waiting with a gun; the origami bird contained a note from Michael reading "GATE." They lock T-Bag in the room; he's going back to Fox River. Don's on the way. As they leave, T-Bag yells that they can't get Scylla without him.

Sucre rejoins the others just as they're wondering what's taking him so long; the card was fully downloaded a while ago. As they get ready to head back to Los Angeles, Roland says he has to use the bathroom first. Instead he sneaks off to a slot he knows is two pulls off from a payout. He is recognized by a casino detective. Roland's got a history of wirelessly looting Vegas casinos. He's been told before that he's not welcome in any Nevada gaming establishment. The detective finds the device, and snaps it in half. Roland rejoins the others. He's downloaded Scuderi's card to his laptop, but there's still one more card to get; and it took Roland months to build the device.

T-Bag tries to use his prosthetic hand to open the lock, but drops it outside of the cage. Don, who has already freed Bellick and Trishanne, arrives to have T-Bag taken into protective custody until they've got Scylla; then he'll turn him over to the Illinois DOC. The next step getting the device that can decode Scylla. There's a tunnel down the hatch that leads to the building where Pad Man's office is. Security there is tight, but Michael says the substructure is completely exposed. Once they get the last card, it shouldn't take more than 24 hours to get in there. Meanwhile, they'll need around-the-clock access to GATE; Michael asks Don to get them suits and fake IDs so they can pretend to be IRS agents auditing the books. Suddenly a phone rings, but not one of theirs. Don finds it hidden with an envelope under the trash can. It's Gretchen, saying she's interested in Scylla. She tells him to open the envelope. It's a color copy of page 87 of the bird book, the one with the red dot. Michael didn't know the book went past page 77. There's a lot more he doesn't know. Gretchen says that unless she sees T-Bag, they're not getting the rest of the book. Michael grabs the phone, demanding to know who this is. "Hello, Michael," says Gretchen. Michael recognizes her voice, and it hits him like a ton of bricks.