Our episode opens as Daryl stares down the prisoners we saw at the end of the last episode; it's his crossbow against the gun held by one of the prisoners as Rick, Maggie and Glenn struggle to put a tourniquet on Hershel's leg. The room is chaos, with walkers at one door, everyone shouting at cross purposes and cafeteria furniture being repurposed as a gurney. Making their way out of the cafeteria and back through the dark halls into the living area, they leave behind the prisoners, who follow them rather than remaining locked in the cafeteria with Hershel's leg. Once they reach the living area, the rest of the survivors help try to bandage Hershel, Carol taking point because Hershel has taught her as much medical knowledge as he can so that he has an assistant when Lori gives birth. Daryl returns to wait by the door for the prisoners to emerge, holding his crossbow on it and watching them as they do. The prisoners come into the light and Tomas, the group's leader, objects. As Glen Mazzara has said in interviews: "Tomas is the leader. Tomas is the alpha male. He's the one who is in charge and he is the one who has set the rules and he did before the apocalypse, he's been doing that since, and suddenly, here's Rick telling him, 'This isn't even your prison any more.' Tomas is not going to stand for that."
Tomas demands that Rick's band of survivors turn over the cell block they're living in to him. Daryl responds by telling the prisoners that they've been "pardoned by the state of Georgia" and are free to go. The other prisoners seem more eager to cooperate or flee than to get into an armed conflict, but Tomas has a gun and he's suspicious of Rick's group. After all, he figures, a group of civilians breaking INTO a prison probably can't mean anything good. Rick goes to handle the situation with the prisoners, which begins to escalate rapidly as T-Dog joins them with another gun. It deteriorates into a shouting match before Rick joins them, having told Glenn to stay with Hershel. "What'd you do, rob a bank or something?" Tomas asks Rick. "Take him to a hospital." It's then that the survivors realize the prisoners haven't just survived the events of the last few months, but have done so entirely while holed up in the cafeteria. It falls to him to explain to the prisoners that society and government have collapsed, that almost half of the world seems to be dead. When they initially disbelieve him, he brings them out into the yard to show them the hordes of dead walkers, and then the undead ones on the other side of the fence.
Rick also tells them that everyone is infected, and that they plan to stay at the prison for the time being. Tomas suggests they camp out in the yard, and pulls a gun. Ultimately they settle on the notion that the prisoners will clear a cell block, with help from Rick and his group, in exchange for half the food left in the cafeteria. He tells them that if they come anywhere near the survivors, he'll kill them, terms Tomas agrees to. Back in the prison, the women and Glenn have stopped the bleeding on Hershel's leg, and start discussing how to find the infirmary to get supplies for Hershel. Rick and the other men follow the prisoners to the pantry, where in spite of repeated assurances that there wasn't much left, they find an entire room full of food. When Rick opens a door to find out what else is in there, he begins to gag--it's a room that the prisoners had dedicated, for the last several months, to using as a toilet. At Hershel's bedside, Glenn tells Maggie not to blame herself for what happened to Hershel and tries to convince her not to give up hope that her father won't make it. In spite of that, she goes to Beth--who is tearing pieces of pant legs off of Hershel's clothes so they don't drag on the ground--and tries to convince her not to get her hopes up. The men come with some of the food, and Rick tells Glenn to handcuff Hershel to the bed in case he wakes up as a walker. He then tells Lori about the deal he struck with the prisoners, saying that he's not sure if it's going to work but that hsi only other option seems to be to kill them. She tells him that she understands if he has to, and to do whatever he has to do to keep the group safe, and to do it with a clear conscience. As Rick, Daryl and T-Dog prepare the prisoners to take a cell block full of walkers, Tomas complains about the series of blunt instruments being provided to them as weapons, asking why he would want to use those instead of his gun. Daryl explains to him that the gun will just draw a crowd of walkers to you, and that you don't fire one unless your back is against the wall and explains to them that anything but a strike to the brain is useless against the walkers, and urges the prisoners to go into battle with his group, backs together in a circle, like we saw them doing with Maggie during the premiere. Back at Hershel's side, Maggie asks the other survivors to be alone for a minute, and tells her father that he doesn't have to fight anymore, that she'll be alright if he wants the peace of death. Back in the block the men and the prisoners are clearing, the formation doesn't hold together for long before the prisoners ignore all advice, bolt off in all directions and start gang-stomping walkers. Rick and the others seem equal parts frustrated and vaguely amused. The rest of the group is back in Hershel's cell, waiting for him to come to (or not), when Carl walks in carrying a duffle bag. He tells the others that he found the infirmary and brought back supplies, which equal parts delights everyone and mortifies his mother, since he was wandering around the grounds by himself. He doesn't see what the big deal is--and tells her to get off his back--then tears off in a huff when his crush Beth scolds him for talking to his mother like that. When one of the prisoners (Big Tiny) finds himself cornered by a pair of walkers--one of whom slips his handcuffs by pulling so hard the hand falls off--Rick takes one out with the machete and Tomas blasts the other three times with his revolver, drawing a stern look from Rick. It's too late, though, as Big Tiny's skin was broken during the encounter. At the makeshift infirmary, Carol asks for Glenn's help in the yard, saying that she needs it now. The men and the prisoners are back at the site of the brawl with the walkers, discussing how to handle Big Tiny's injury. The survivors have already more or less told the prisoners that they have to put the man down, but one of the prisoners notes that they managed to save Hershel (at least so far) by amputation. Rick says that because Big Tiny's injury is on his shoulder blade, that's not an option. They discuss quarantine versus death, but the discussion is abruptly interrupted when Tomas first knocks Tiny down and then batters him brutally (using one of the anti-walker weapons) over a sustained few seconds while he's on the ground. Outside, Carol asks Glenn to help her prepare for Lori's birth by killing a walker that she can use for "practice." Even if Hershel survives, she explains, it's unlikely he'll be in any condition to help her when the baby comes. She says that Lori is overdue, and that since she had Carl by C section, it's likely she'll be forced to operate when the time comes. Finally ready to clear the cell block itself, Rick gives Tomas a set of keys and instructs him to open one of the double doors at a time so that they can control walker traffic and ideally kill them one or two at a time. Tomas, instead, whips the doors open and then swings his weapon at Rick, with the pretense of aiming for a walker. "S--t happens," he explains, then moments throws a walker at Rick during the melee that ensues with about fifteen walkers. Daryl takes out the walker before it can hurt Rick, obviously, but the result is a brief showdown between Rick and Tomas. When Tomas defends his actions saying that the walker in question was coming for him, Rick says, "Yeah, I get it--'s--t happens'," and splits Tomas's skull with the machete. Seeing this, Andrew (Tomas's right-hand man) screams and swings a baseball bat at Rick, but Rick is ready for it and kicks him to the ground. Andrew flees into the prison, pursued by Rick, while Daryl holds Oscar and Axel at crossbow-point while T-Dog holds Axel at gunpoint. Axel immediately tries to distance himself from the events that just happened, but Oscar remains stoic. Andrew makes for an exit, realizing only too late once he's outside that there ware about ten walkers in a small area with him where he's ended up. Rick closes the door shut behind him, and Andrew begs to be let back in, but Rick just tells him to run, then turns and we can hear the sounds of Andrew being attacked and consumed on the other side of the door. Back in his room, Hershel stops breathing. Maggie steps away to let him die in peace, but Beth sees events unfolding, freaks out, and screams for help. Lori comes, gives Hershel CPR and successfully wakes him--although there's a moment where it seems he's clung to her face because he's a walker. Luckily, nobody kills him during this moment. After Axel pleads for his and Oscar's lives, Rick, Daryl and T-Dog bring the pair into the cell block they were clearing and leave them there. Daryl relates to the men a little bit, telling him he's sorry for their losses after Axel expresses regret over the bodies on the floor. Rick leaves more or less without a word, telling them that this is their part of the prison now but it will be locked down. T-Dog tells them that they should take the bodies out into the yard and burn them. The men rejoin the rest of the survivors just in time to see Hershel wake up--fully this time, and not as a walker. He holds his hand out to Rick, apparently to thank him for what he's done, and Rick hands it over to Hershel's daughters. Outside, Carol begins operating on her walker-cadaver, but is clearly being watched by someone on the periphery of the property. Whether Andrew could have survived is unlikely, but there are of course plenty of other threats out there. Finally, Rick and Lori get together and put to rest some of the tension that's existed between them since Rick killed Shane, with Rick parroting some of her own kind words, directed at him in the season premiere, back to her and then heading back indoors.