After being kicked out of Hershel's farm, Rick Grimes and the group of survivors find what they may finally call home: a prison. However, they soon discover that it is infested with biters. After clearing out some parts of the prison, the starving group heads to the cafeteria. In there, they find enough food for at least a year, and four inmates: Andrew, Dexter, Axel and Thomas.
The inmates show Rick and his group many parts, yet unexplored by them, such as the laundry room. Later on, Rick, despite some of the others' opinions, goes back to Hershel's farm and takes the old man, Glenn and his family to the prison, as the farm could no longer be considered safe. Once everyone is asleep, Chris and Julie, after having sex, talk about their pact. They would kill each other at the same time, so they could be together forever. Unfortunately, Chris pulls the trigger before the girl, killing her. Tyreese arrives at the scene a bit later, followed by Rick. That's when they find out that they're all infected, as Julie comes back from the dead, although she wasn't bitten. Chris, again, shoots the young girl, causing Tyreese to go mad and choking the boy to death.
After the previous night's discovery, Rick goes back to the camp, and talks to a zombified Shane, only before shooting his old friend. Meanwhile, at the prison, Tyreese, Glenn and some others go clear the gym of the biters. Unfortunately, after seeing his own daughter becoming a zombie, Tyreese goes mad and starts beating up the roamers, but ends up falling before dozens if them. At that exact moment, Thomas, one of the inmates chops off the heads of Hershel's younger daughters.
On the next day, Lori blames Dexter for killing the young girls, as he was first locked up because of murder, while everyone thought Thomas was charged with tax fraud. As Rick arrives at the prison, and hears what happens to Tyreese, he goes to the gym only to make sure he died. There he finds the big man alive. Meanwhile, Thomas plans on cutting Andrea's head off. She manages to take him outside, where the group is. After seeing what the psycho is trying to do, Rick beats him until he is unconscious. Then, he decides that Thomas will be hanged. Meanwhile, a locked up Dexter tells his boyfriend Andrew to get all the weapons he can, as they'll either kick the group out of the prison or kill them.
Rick locks up Thomas before he is hanged. Patricia, Ottis' ex-girlfriend tries to free him, but the psycho ends up attacking her. Fortunately, Maggie shoots the man before he can kill Patricia. After the mad man is dead, Dexter points a gun to Rick's head, telling him to get out of his house, or die.