The episode begins with unfamiliar survivors watching from the opposite side of a metal grate inside the prison; the familiar survivors on the other hand attempt to secure Hershel, whose leg was recently hacked off after being bitten. Zombies burst into the room only to be stabbed in the neck by T-Dog. Daryl then trains his crossbow on the human strangers and the gang backs out of the room and into the dark prison hallways, in a hurry. They make it back to their cellblock and put Hershel on a bed. He is bleeding badly, and seems in a really bad shape.
Daryl watches the door to the cellblock and is soon greeted by the other survivors all dressed in prison guard clothes. "Today's your lucky day, fellas," quips Daryl, aiming his crossbow. "You've been pardoned by the state of Georgia. You're free to go" he adds. An argument then ensues. The prisons don't like taking orders. Rick enters the room and encourages calm. It turns out that the prisoners had been locked in the cafeteria for 10 months and apparently don't have any idea what's happening outside. "There's no hospital, police it's all gone," Rick explains. "No phones. No computers. Far as we can see at least half the population has been wiped out" He exclaims, trying to explain the state of affairs. Considering the circumstances, the prisoners take the news rather well. "This is our prison, we were here first" says the inmate leader.
Rick then negotiates a deal; if the prisoners give up half of the food in the cafeteria, then Rick and company will help clear out another cellblock for the inmates. But if the inmates ever leave their new cellblock "I'll kill you" Rick promises. Sensing Rick is not at all bluffing, the inmate leader agrees to the terms, as the terms seem reasonable enough to him. Back inside, Carol and Lori tend to Hershel, who has lost consciousness. Carol reminds Lori that she'll have to deliver a baby in these conditions. Lori hardly needs a reminder, as she is already dreading that fact. From the looks of it, it's all she thinks about these days. Glenn comforts Maggie, who fears that her father will die and then wake up. Maggie then visits her little sister, Beth. "I don't want you to get your hopes too high" warns Maggie, who says that, without Hershel, there is no doctor in the group. Rick returns with a few boxes of nonperishable cafeteria food. He has a heart-to-heart with Lori, who says she understands if Rick kills the gang of inmates.
Rick scoffs he has heard Lori go back on such words before, and doesn’t believe she really means what she is saying. "You're not a killer I know that," says Lori, who admits that she isn't going to win any wife or mother of the year awards. "You do whatever you got to do to keep this group safe “she adds, putting the onus on Rick. Rick nods in assurance that, he no doubt will. Rick, Daryl, T-Dog, and the inmates then make their plan for clearing out the cellblock. They will stay in a tight circle. They will aim for the heads of the walkers, as it would be easier to kill them off quickly if they do so. Maggie, in the meantime, cries over Hershel, who has been handcuffed to the bed just in case he turns. She tells her dad that she will be ok without him if he has to go. "Thank you" she whispers before kissing Hershel gently on the cheek.
Rick and company then head inside the adjoining cellblock, which is almost pitch black. Soon, walkers stumble into sight. The inmates immediately break the circle and rush the walkers, attacking viciously. They beat the walkers in the chest and arms and legs. Rick shakes his head, dismayed at the fact that they did not act according to plan. Carl on the other hand returns with a huge bag of medicine. He explains that he went to the infirmary all by himself, killing two walkers in the process. Lori is furious and tells Carl he can't go off alone anymore, as it’s too risky to do so. He yells at Lori, prompting Beth to tell Carl he can't talk to his mother that way. Carol, who has a crush on Beth, is stung by her sharp words and runs away. One of the inmates, just then reveals that he was scratched by a walker.
The group argues over what to do, they ponder whether to quarantine him, or leave him alone. Just as they are doing so, the lead inmate suddenly bashes his cellmate on the skull. Problem solved. Rick eyes the leader, who is clearly a killer himself. Carol and Glenn head outside. Because Carol is worried that Lori will give birth, probably a C-section and Hershel is down. Which in other words means, Carol will have to perform the delivery, but she doesn't have the skills, which is clearly worrying her. Therefore Carol is planning to kill a few walkers, drag them inside, and then practice cutting open their bellies.
Rick and company open a pair of doors to reveal dozens of walkers, much to their horror. In the melee, the prison leader shoves a walker at Rick. Rick is knocked over and saved at the last second by Daryl. Moments later, all the walkers are dead and Rick confronts the leader, who claims it was an accident. It clearly wasn't an accident and Rick is taking no chances. He buries a machete in the leader's head. The youngest inmate then takes off running into the new cellblock and Rick follows. The young inmate runs into a fenced off yard filled with walkers and Rick closes the door behind him. "You better run," Rick says. The prisoner does just that and is quickly overtaken by walkers. Daryl and T-Dog keep their guns trained on the remaining inmates; Oscar and Alex.
Alex cries and pleads for his life, after seeing what Daryl and company just did. Oscar though, refuses to beg. "You do what you gotta do" he tells Rick. Rick decides to let them go into the cellblock. "From now on, this part of the prison is yours," he tells Alex and Oscar. So the pair is left alone in their new home to fend for themselves. Rick and company return to their cellblock to find that Hershel had briefly stopped breathing and was brought back to life by Lori. Hershel then opens his eyes and smiles at his daughters. From the looks of it Hershel might be ok, after all. Later, Carol performs practice surgery on a dead female walker, just as she had planned. An unseen individual watches the grisly scene from the brush some yards away.
Rick and Lori have another heart-to-heart. "For the record, I don't think you're a bad mother" he says. Lori tries to talk about their relationship, but Rick only thanks her for saving Hershel and apparently is in no mood to talk about anything else. Rick puts his hand on his wife's shoulder, but does so, tentatively. "I'm grateful for what you did" he says. Then he walks away, leaving Lori alone and fighting back tears. The episode ends at this point.