The BAU is called in to investigate the murders of two guards, Officers Keith Rivers and Rudy Hightowers. Both were stabbed to death and had socks stuffed into their mouths.
The team discover that both murdered men each had seven broken fingers.
The captain of the guards, Dale Shavers expresses resentment to Morgan and Kate over the fact that his guards aren't getting the equipment they feel that they need, and that the management of the company only cares about the amount of profit they can get, even to the point of putting guards' lives in danger.
One of the prisoners - Randall Jefferson Jones - is distributing meals when he warns a fellow prisoner to keep quiet and not say anything to the feds.
Rossi and Morgan interview the leader of a gang - Julio Watson - who tells them he hated the two dead officers, but that he didn't kill them.
The preliminary report on the dead bodies indicates their fingers were broken post-mortem.
Reid goes through all of the prisoners' files and discovers that one inmate is missing - Devon White.
Randall Jones -- who gave the warning -- is scalded to death while in the showers. A sock is shoved into his mouth.
Reid notices that Jones shows signs of sexual assault.
Officer Tom Polinksy opens his locker to find that the picture of his daughter has been defaced.
Garcia discovers that the two dead guards have been having suspicious banking activities. She theorizes they were having bets with each other.
Reid discovers that the missing Devon White had had extensive disciplinary write-ups issued by the two dead guards, and that he had made multiple trips to the infirmary for fight-related injuries.
The team interviews prisoners to find out more about Devon White -- who they describe as a good kid, a reader who helped them with their studies.
Captain Shavers takes prisoner Patrick Butler down to solitary, demanding to know who was helping him. Butler resists and tries to fight the captain but Shavers beats him to death instead.
Reid figures out that the broken fingers aren't related to the number seven but to cell #34.
Captain Shavers issues a veiled warning to Tom Polinksy prior to his interview with Morgan and Kate, implying that if he said anything his daughter would be in danger.
Polinksy opens up to the team about Shavers' crimes, and about how they got rid of White's body. He told them he stumbled onto a scene where Shavers and a bunch of guards were forcing White and Butler to fight, even though they were closer than friends.
While Polinksy is still being interviewed, Captain Shavers frees a bunch of prisoners, with the intention of getting them to kill Polinksy and the BAU team. The prisoners break into the interview room and attack Morgan, Kate and Polinksy, overpowering them.
A bunch of prisoners interrupt the abduction and stop them from hurting any of them too badly. A SWAT team rescues them.
When the Warden and the rest of the BAU arrive at the control booth, Shavers realizes his plan didn't work and he's been caught so he shoots himself.