Darryl and Glen get back to the farmhouse and report that Randall was zombified without any bites, plus they found Shane's tracks comingled with Randall's. Out in the field, Carl is trying to put together what happened, wondering how Shane died and how he got turned. Rick isn't ready to answer the first part of that yet. Then they hear the approaching walkers and run like hell. The others, standing on the farmhouse porch, hear the groaning of the herd too and lock and load. Rick and Carl take refuge in one of the barns and are quickly trapped. Lori has discovered that her son is no longer in the house (seriously - these are the worst parents ever for keeping track of their child's whereabouts) and starts getting hysterical. Rick decides that letting the zombies into the barn and then setting it on fire is a good idea; the zombies moan and burn, but don't die right away because it's not like the fire crushes their brains.
A bunch of the farmhouse crew jump into vehicles, planning to shoot a bunch of walkers and then hopefully lead the rest away from the farm. Note: if Darryl gets killed off, I will, as previously noted, become extremely cranky. Jimmy drives the RV around to the back of the barn to try to rescue Rick and Carl. The RV stalls and gets overrun, Jimmy quickly and bloodily eaten, while Rick and Carl climb down the outside of the RV and scamper off.
Carnage, lots and lots of carnage, driving and shooting, driving and shooting. Andrea realizes that there are too many walkers and that they'll run out of ammo before they make a dent. Herschel stands in front of his home, methodically shooting zombies; meanwhile, Lori and Carol are basically f'ing useless, screaming for Carl, until Lori FINALLY picks up a gun and brings down a few walkers. The zombies close in and Lori screams at Herschel to leave. He won't give up his home. Lori, Patricia and Beth run for it but the zombies tear Patricia away and munch on her. Andrea jumps out of the truck T-Dog is driving to rescue stupid Carol and they are soon surrounded. Maggie and Glen's car is nearly overrun until he yells at her to get the hell out of here - they have to get off the farm now! Herschel almost gets eaten but Rick saves him in the nick of time, dragging him into a truck. They drive off, not knowing that Andrea is still alive. Darryl hears Carol screaming for help as she runs along a fence line. She climbs onto the back of his chopper and they drive off.
After the humans have left, the zombies lose interest in the farm. They begin to move off, searching for their next meal. In a gorgeous shot, the burning barn collapses behind them, silhouetting them.
Ooh! Trailers for both Prometheus AND The Cabin in the Woods. Squee!
Everyone is separated, driving through the woods at random on dirt roads. Maggie is freaking out so she pulls over to let Glen drive. He tries to calm her down, telling her that he loves her and has for a long time, and he's sorry he didn't tell her that before. She gets a grip and they drive on. The plan seems to be to rendezvous at the highway where they had left supplies for Sophia. Rick, Carl and Herschel are the first to arrive. Carl freaks out when his mom isn't there. A depressed-sounding Herschel says that he'll wait to see if any of the others show up (and if a zombie gets him, so be it), but Rick should take his son to safety. Rick's all, no, we'll stick together. They wait, occasionally dodging the odd zombie.
Darryl and Carol make it to the meeting place, then Maggie and Glen, then Lori, T-Dog and Beth. Hugs and tears all around, then they take stock and realize that Andrea's fate is uncertain. Darryl is ready to go back for her but Rick points out that she's either dead or she's someplace else - she wouldn't stay at the farm. They've got to stick together and keep moving, and try to find a safe place where they can regroup. They get into their vehicles and drive off.
Amazingly, Andrea has survived the night and is running as best she can through the woods with some tenacious walkers right behind her. One comes up on her and she bludgeons it to death to try to save ammo. Then she has to shoot a bunch of them until her gun comes up empty. Speaking of empty, Rick's truck is out of gas. He says they'll camp for the night, then forage for gas and other supplies in the morning. Maggie says she and Glen can make a scavenging run now but Rick insists that they stick together for safety.
Around the campfire, the group talks about how Shane killed Randall (Darryl has put that together) and then Randall turned without being bitten. Rick finally admits it: we're all infected, the CDC guy told me we're all carriers. (Frankly, I don't remember that but I'll go with it.) Everyone is absolutely furious with him for not having shared that bit of information sooner. Rick walks off. When Lori goes to him, he tells her what happened between him and Shane. "I gave him every chance," he says, "and he kept leading me further out. He pushed me and I let him ... I wanted him dead." He says that when he saw Shane turn, that's when he knew Jenner (CDC guy) was right. When he tells her that Carl was the one who put Zombie Shane down, she staggers and then strikes out at him. She goes back to the group and he watches her go, his gaze hardening, looking not far off a zombie himself.
Andrea is still fighting for her very survival as the sun goes down, beating in zombie skulls. It looks like she's whittled the chase group down to just a few. The last of them gets her down and it looks like it may be over for her - until the zombie's head is sliced off by a hooded stranger carrying a big ol' sword. Said stranger stands above Andrea, two armless zombies (!?!) leashed to him with chains. Andrea's like, thanks but WTF?
At the campfire, everyone is fretting about what Rick did (or didn't) tell them, and wondering if they should strike out on their own. They hear a noise out in the dark and start to freak out. Rick has had enough: "We're sticking together. I'm keeping you all alive - I killed my best friend for you all. My hands are clean." Now he's starting to sound like Shane. No one will look at him so he's like, fine, you all can just fuck off and try to survive off on your own. When there are no takers, Rick growls, "If you stay, this isn't a democracy any more." Now they're all looking at him and none too friendly-like.
The camera pulls back, revealing what looks like a fort or a prison not too far away: protected, defensible and quite possibly just what they need. Wonder if the hooded zombie-enslaving swordsman has anything to do with that place? Jeez, I need to read the books!