Seconds after amputating Hershel's leg with a hatchet in the prison cafeteria, Rick and the gang drag him right back out, now that the walkers have apparently gotten bored. The five prisoners who have been locked in there for ten months try to follow, but Daryl, T-Dogg, and Rick make sure they don't make it to the cell block where the group has set up housekeeping. There's a bit of a standoff between Rick and the inmates' hotheaded leader (the only one of them with a gun) about exactly whose prison this really is, but they come to an uneasy settlement wherein Rick, Daryl, and T-Dogg will help the prisoners clear out their own cell block so they can stay nice and clear of our group. You know, it's either that or kill them, and Lori tells Rick to do what he has to do, to which Rick has a pretty awesome response.
Meanwhile, Hershel and his bloody stump are parked on one of the cell bunks so he can go about either bleeding out or turning into a walker, whichever comes first. Glen's job is to stay on top of him in the event of the latter, which he mostly does until Carol (who Hershel has drafted as his medical student) drags him out to the yard to help her collect a walking cadaver on which she can practice doing the C-section she's likely to have to perform on Lori. Maggie seems ready to give up on Hershel while Beth keeps hope alive and New Improved Carl quietly raids the infirmary to get much-needed medical supplies, only to get yelled at for it by Lori. But Lori's not done making bonehead moves; she's stupid enough to give Hershel mouth-to-mouth when he stops breathing. The good news is that when that brings him back, it's in the right way.
The expedition to clear Cell Block D doesn't exactly go smoothly. Rick, Daryl, and T-Dogg are saddled with five zombie-hunting neophytes who have a shallow learning curve, and during one of the many melees, one of the prisoners is scratched. The prisoners' leader kills the man in cold blood, and during a later melee, tries to kill Rick as well. Rick ends up killing him right back, as well as one of his accomplices, but allows the two surviving prisoners to enter Cell Block D alive, though not quite in luxury.
When our guys return safely to Cell Block C, Hershel is not only still alive, he shows no signs of zombification. In fact, it's been such a successful day that in private, away from everyone else, Rick is even able to say something nice to Lori. Better yet, he keeps it brief.
After last week, when Rick hacked off Hershel's zombie-bitten leg in view of five shocked inmates who have been presumably trapped in here since Day One, we pick right back up in the cafeteria one second later. Obviously the five once and present inmates and our heroes are pretty surprised to meet each other. One of the current residents draws a gun (the only one so armed; their arsenal is less Max Payne and more Clue) upon learning that Hershel's been bitten, but T-Dogg holds them at bay while Glenn ransacks the adjoining room they just stepped out of for medical supplies and Rick leads the effort to drag Hershel back out of there before he bleeds out. They make their way through a flimsily barricaded door and one helmeted walker courtesy of T-Dogg before they head back out, leaving behind five very confused dudes and half of Hershel's leg. This is not the rescue squad they've been waiting for.
The inmates decide to follow, brandishing their lame-ass weapons, while the invasion force returns to their cell block with T-Dogg and Daryl acting as rear guard. With Hershel down and laid out on the bunk in his cell, Carol takes over as the group's medical expert (we'll later find out that Hershel's been giving her lessons, so that she'll be useful during Lori's delivery), but Hershel's bleeding so quickly that it's not looking good. Oh, and there's also the thing where he's been BITTEN BY A ZOMBIE.
The inmates come out to the assembly room where Daryl is waiting for them, crossbow at the ready. Clearly nobody had to tell anyone that these guys weren't to be allowed into Cell Block C, where the group has set up housekeeping. Daryl tells them they've been pardoned and are free to go, not bothering to try to sound any more official than he looks, but the one with the gun doesn't seem as grateful for their freedom as the others are. Indeed, he's the only one who thinks it's odd that a bunch of people broke into a prison and aren't bringing a wounded friend to the hospital, which tells him that it's not any safer outside than in. A confrontation starts escalating with T-Dogg entering the room, so of course Rick has to go back and sort it out personally. But not without first urgently telling Glenn not to leave Hershel's side. "If he dies, you need to be there for that." I assume he doesn't mean in the emotional sense. Doing what needs to be done might prove challenging in Maggie's presence, but Glenn assures Rick that he's got it. Rick runs out to the other room, trustingly leaving the grate open for New Improved Carl to close and lock behind him without being asked, which he does.