At the survivors' camp, Amy hands Lori mushrooms collected from the forest. She asks how to tell if theyíre poisonous, to which Lori replies there's only one way she know of: Ask Shane. Afterwards, Lori herself heads into the forest, where Shane sneaks up on her. "How much time do we have?" Shane asks. "Enough," Lori replies, and the two have sex.
Sealed in a military tank in Atlanta, Rick says over the CB radio: "Whoever you are, I donít mind telling you I'm a little concerned in here." A voice replies that Rick is surrounded by walkers, and advises him to make a run for it while they're distracted eating Rick's horse.
Rick takes a gun and a grenade off the dead soldier in the tank then opens the hatch. He jumps from the tank and runs down an alley, shooting walkers as he goes. Quickly, he meets up with the person who radioed instructions. Rick follows him to a ladder, which they climb to safety.
"Nice moves there, Clint Eastwood," says the young man who introduces himself as Glenn.
Glenn leads Rick down a staircase to an alley, which is free of all but a few walkers thanks to a bus blockade. When the two reach street level, two other people wearing riot gear emerge and beat down the walkers.
The group rushes inside a department store, where a woman named Andrea points a gun at Rick's head, furious at his recklessness. One of the men, Morales, informs Rick his gunshots have attracted scores of walkers. "You just rang the dinner bell," Andrea seethes.
Outside, walkers press against the store's front doors. The glass begins to crack.
A man, T-Dog, tries to radio "the others" but fails to get a signal. He suggests they might have better luck on higher ground.
On the roof, the group finds Merle Dixon — a middle-aged redneck — firing at walkers with a rifle. T-Dog chastises Merle for wasting bullets and attracting more walkers. Merle scoffs at taking orders from a "N——," which sets off a fight between the two.
Merle beats T-Dog then presses a handgun to his forehead, but Rick intervenes, hitting Merle with the butt of the rifle and handcuffing him to a pipe. "Things are different now," Rick tells Merle. "We survive this by pulling together, not apart."
Morales tells Rick there is no refugee center, that was a pipe dream. They're with a small group of survivors staying outside the city, but T-Dog can't reach them on the radio.
"We're on our own," Rick says. With the streets no longer safe, Rick suggests they try to escape underground. A woman named Jacqui, who formerly worked in the city zoning office, says that the building might have access to the sewers.
Glenn and Morales head to the basement while Rick and Andrea stand guard at the front of the store. "Sorry for the gun in your face," Andrea tells Rick. He understands, people do crazy things when they are afraid, but gives her some advice: "Next time," he says, "take the safety off."
Glenn and Morales travel through the sewer until they reach a grated barrier. They discuss ways to cut through, but abandon the idea when they see a walker devouring a rat on the other side.
In the store, Andrea spots a necklace with a mermaid pendant. "My sister," Andrea says. "She loves mermaids." Rick encourages her to take it. As Andrea pockets the necklace, walkers break through the exterior glass doors and begin pounding on the interior doors. Morales and Glenn arrive to report that the sewer is not an option.
Back on the roof, Rick spots a cube van at a nearby construction site. The ignition keys should be nearby, Rick theorizes, but they need to get past the walkers undetected. The group explains that if they hear you, see you or smell you, they eat you. Rick latches on to the scent idea. "They smell dead," Andrea offers. "We don't."
Wearing rubber gloves and rain jackets, Rick and Morales drag a dead walker in from the alley. After acknowledging the man's lost humanity, that he used to be just like the rest of them, Rick grabs an axe and hacks apart the body. He and Glenn then smear the corpse's guts on their jackets. Before leaving, Rick tosses T-Dog the key to Merle's handcuffs.
Outside, Rick and Glenn shuffle through crowds of walkers, unnoticed.
Back at camp, Amy frets over the whereabouts of the group — her sister in particular. Dale, an older man in a sun hat, receives T-Dog's garbled transmission explaining they're trapped. "We do not go after them," Shane insists. "We do not risk the rest of the group."
Back in Atlanta, a rainstorm passes over Glenn and Rick, washing the zombie guts off their jackets. Their human smell unmasked, the two are immediately attacked by walkers. Fighting them off, Rick and Glenn run to the construction site, hopping a fence that's blocking access. Once Glenn tracks down the key, he and Rick speed away in the van.
Rick orders Glenn to radio the group to get ready for pick-up. To lure the walkers away, Glenn drives off in a red sports car, which Rick has hotwired after setting off its alarm.
As the group rushes from the rooftop toward the loading dock, T-Dog reluctantly turns to Merle. He moves to set Merle free, but accidentally slips on the rain-soaked roof and drops the handcuff key down a drain.
"I'm sorry," T-Dog gasps. He runs back to the stairwell and chains the door shut. Merle is left screaming in rage on the roof.
Walkers break through the interior doors and enter the department store.
Outside, with the walkers lured away by Glenn's car alarm, Rick pulls the van up and the group piles in. T-Dog admits to the others he dropped the key, leaving Merle trapped on the roof.
As they escape the city, Andrea asks, "Where's Glenn?"
A wailing red sports car speeds full throttle out of Atlanta. Inside, Glenn screams with joy.