In a flashback to sometime before the apocalypse, Lori waits outside Carl's school and tells a friend about a fight she had with Rick. The friend asks Lori if she still loves Rick. "I'm tryin' to remember how that works," Lori admits.
When Shane pulls up in a police cruiser, Lori realizes something has happened to Rick. "Is he alive?" she asks.
Shane recounts the highway shootout. "How do I tell my son his father's been shot?" she asks. "You don't have to do it alone," Shane replies but Lori knows she must do it herself. Shane watches from a distance as Lori tells Carl the news.
Back in the present, Rick holds an unconscious Carl while running through a field. "How far?" he screams to Shane and Otis, a sturdy Southerner with a rifle, who are running behind him. Otis gestures to keep running and instructs Rick to ask for Hershel. Shane prods Otis to keep moving.
Rick approaches a farmhouse, where an older man, Hershel, meets him on the front porch with his daughters Maggie and Beth, Beth's boyfriend Jimmy, and Patricia, Otis's girlfriend.
"Was he bit?" Hershel asks. "Shot," Rick says, "By your man, Otis."
Hershel rushes Rick inside and then, once Rick lays Carl on a bed, Hershel goes to work with his medical supplies.
Shell-shocked, Rick shuffles to the front porch just as Shane and Otis arrive. Shane wipes blood off Rick.
Rick goes back inside to tell Hershel he has the same blood type as Carl. Hershel warns Rick not to wander far. Otis is distraught, he was hunting the deer and never even saw Carl. Hershel adds that the deer that Otis shot slowed the bullet down but also broke it into six fragments. These need to be removed.
In the forest, Lori frets over the sound of the gunshot. Daryl offers that Rick might have killed a walker; Lori knows Rick wouldn't risk the noise. The group forges on.
"I'm sorry for what you're going through," Andrea tells Carol as the group mobilizes. "I know how you feel." Carol thanks Andrea for the sympathy. "I just keep hoping and praying she don't wind up like Amy," Carol says. Daryl insists, Sophia will be fine.
On the highway, Dale scavenges for car parts before noticing that T-Dog is feverish. T-Dog's infected arm needs antibiotics or he'll die.
"Wouldn't that be the way?" T-Dog laughs. "Theodore Douglas gets done in by a cut on his arm." Dale encourages T-Dog to help look for medication in the abandoned cars.
Back at the farmhouse, Rick waits impatiently for news on Carl. "Why did I let him come with us?" he laments. Shane urges Rick not to blame himself. Rick curses having survived long enough to find his family, only for Carl to get shot.
In the bedroom, Carl screams as Hershel removes a bullet fragment. Patricia, meanwhile, readies Rick for a transfusion. Carl passes out. "One down," Hershel says holding the fragment. "Five to go."
After the transfusion, Rick insists he needs to find Lori but since Hershel needs Rick to stay to donate more blood for Carl, Shane assures Rick he'll get her for him. Hershel interrupts to say that Carl needs major surgery or he'll die, but he can't perform the surgery without a respirator. Otis suggests they get the medical supplies they need at the high school - where FEMA set up a trailer - even though the place is likely overrun by walkers. Shane and Otis go for the supplies; Maggie offers to find Lori.
Outside the farmhouse, Otis loads his truck. Rick offers Otis his Python. "I'll bring it back in good shape," Otis promises.
Back at the highway, Dale is unable to find antibiotics. T-Dog, delirious from fever, tells Dale that they should make off in the RV before the others return.
In the forest, the other survivors march toward the highway. A walker suddenly attacks Andrea, crawling on top of her but Maggie arrives on horseback and knocks the walker off with a baseball bat. Afterward, Maggie tells Lori that Carl's been shot then pulls her onto the horse.
Back on the farmhouse porch, Rick and Hershel talk about the epidemic. Hershel believes mankind will eventually beat the disease. "There is no cure," Rick says. Hershel refuses to believe it.
When Maggie brings Lori back, Lori tearfully caresses her son before grilling Hershel on the upcoming surgery. Hershel assures her he's done similar procedures before, even as he admits he's not a doctor. He's a veterinarian.
"You're completely in over your head," Lori says. "Aren't we all?" Hershel replies.
Shane and Otis approach the walker-infested high school. Shane finds road flares in an abandoned squad car's trunk then lights them to distract the undead so he and Otis can enter the medical trailer.
Back at the highway, Glenn tells Dale about Lori and Maggie. They decide that Dale, Carol, Daryl and Andrea should stay another night on the highway in case Sophia returns, while Glenn should take T-Dog to the farmhouse for medical attention. Before they've left, however, Daryl pulls a bag of antibiotics from Merle's motorcycle. "First class," he boasts to Dale. "Merle got the clap on occasion."
Back at the farmhouse, Carl's blood pressure continues to drop. Hershel says they can't wait much longer.
Meanwhile, Shane and Otis collect supplies from the medical trailer. When leaving the trailer they catch the walkers' attention, forcing them to run to the school for safety. Shane blasts the school's front doors with his shotgun then slides a security gate across the doorway. Walkers crash against the gate, desperately reaching for the two men now trapped in the entryway.