Rick solemnly drives back to the prison after exiling Carol.
In cell block A, Hershel, Glenn and Sasha intubate one of the survivors, Henry, who's become violently ill. Glenn asks how long the breathing apparatus can keep him alive. "As long as it has to," Hershel replies.
Hershel and Glenn find another survivor, Mr. Jones, dead inside his cell. They load the body on a gurney and wheel it outside to prevent the others from seeing. Glenn remarks that Hershel's never had to put down a patient, then stabs Mr. Jones in the head as he starts to turn.
Later, Maggie and Hershel talk on opposite sides of the execution chamber's observation window. Hershel tells a panicked Maggie that Glenn is fine - just resting after helping him tend to patients - and refuses her offer to assist in the sick ward.
Afterwards, Glenn thanks Hershel for not telling Maggie about his true health condition, explaining she would rush to his side if she knew.
Back outside, Maggie lets Rick in through the perimeter gate. He tells her he banished Carol for killing Karen and David but plans to inform only Hershel for now. Maggie agrees it was the right thing to do. She then updates him on the fence situation, saying the cluster of walkers is becoming unmanageable.
Rick visits Carl in quarantine to drop off a bag of food from his supply run. Carl insists he's healthy and offers to help, but Rick refuses.
Meanwhile, Hershel checks on Dr. S, who is near death. Dr. S tells Hershel that patients are reaching "End Stage," from which there is no recovery. "If you're not ready to lose one," he tells Hershel, "you're gonna lose them all." Hershel maintains they're not that desperate, but Dr. S opens a crate under his cot filled with guns and ammunition and warns Hershel to prepare.
Hershel starts to shut all the cell doors. Another patient dies. Sasha fetches the gurney but Hershel urges her to rest. He wheels the body outside the cell block and, after covering the face with a sheet, stabs the patient himself.
Through the observation window, Hershel tells Rick they've lost three patients. "When we get past this thing, it's not going to be like how it was, is it?" Rick observes. Rick then tells him about Carol.
Afterward, Hershel finds Sasha collapsed in her cell and gives her an IV bag. As he tends to her, a female patient dies and turns in a nearby cell.
Meanwhile, Maggie and Rick shore up the fence as the cluster of walkers pushes against it.
Back inside the cellblock, Glenn is tending to Henry when he's seized by a coughing fit. Glenn falls to the floor, blood gushing out of his mouth. Lizzie finds Glenn just as Henry reanimates on his cot.
The female walker leaves her cell and attacks Hershel. A man is about to shoot the female walker when another walker - the man's son - bites his arm. He accidentally shoots another patient instead.
Rick and Maggie hear the gunshots. Rick tells Maggie to investigate while he stays behind to reinforce the fence. He fetches Carl to help him.
Meanwhile, Lizzie lures the Henry walker away from Glenn, but trips and falls. Before the walker can bite her, Hershel manages to throw it onto the netting between the second and first floors of the cell block.
Hershel then puts Lizzie and Luke in a cell and tells them to stay put. He checks on Glenn, who's now choking on his own blood.
Hershel runs to Dr. S's cell to retrieve the guns. Dr. S has turned and lunges at him. Hershel stabs Dr. S through the eye.Outside, Carl helps Rick prop up the fence with wooden posts, but their efforts are futile: the fence collapses and walkers stream through. Rick and Carl flee into the prison courtyard as the walkers fill the dog run behind them.
Rick and Carl arm themselves with automatic rifles and ammunition. When the walkers break through the inner fence, father and son methodically shoot them dead.
Meanwhile, Hershel loads one of Dr. S's shotguns and lures walkers into the observation tower - out of Lizzie and Mika's sight - to shoot them.
Unable to break down the door to cell block A, Maggie shatters the glass to the observation window and jumps through.
Hershel finds Glenn still choking on the floor and remembers that the intubator is attached to Henry. Maggie rushes into the cell block and sees Hershel struggling to retrieve the tube from Henry. She kills Henry and, with Hershel, rushes to Glenn's side to administer the tube.
As Rick and Carl pick off the straggling walkers, Daryl and his crew return. Tyreese runs inside and comforts Sasha in her cell. Maggie urges Hershel to rest while she and Bob tend to Glenn.
Hershel enters Dr. S's cell. He closes Dr. S's remaining eye and opens his Bible, but finds himself unable to read it. Hershel starts weeping.
The next morning, Michonne loads the walkers' corpses onto a flatbed truck for disposal.
Hershel informs Tyreese that Glenn survived the night and is breathing on his own. When Daryl asks about Carol, Hershel suggests he talk to Rick.
In the garden, Rick and Carl notice that their crops are beginning to ripen. Rick offers Carl a bean and tastes one himself with satisfaction.
Hershel offers to go along with Michonne to dispose of the corpses. As they drive off together, they fail to notice someone watching from the treeline: It's the Governor.