10/21/2013 03:15 pm ET Updated Dec 06, 2017

'The Walking Dead' Recap: The Prison Gets 'Infected'

Note: Do not read on if you have not yet seen Season 4, Episode 2 of AMC's "The Walking Dead," titled "Infected."

After just the second episode of season 4, we know that last week's premiere is as close as the Prison is going to get to normalcy for a long time. The physical security, budding romantic relationships and Rick's new farmer status to which were just introduced are all threatened in "Infected," both by a deadly virus and a deadly paranoia.

The episode opens with yet another new threat: someone has been feeding live rats to the horde of walkers outside the fence in the middle of the night. Inside the prison, Tyreese and Karen are canoodling, sharing their feelings about the recently departed Zach and getting way too close to each other for both of them to survive this episode. To add insult to inevitable injury, Tyreese serenades his girl with "I've Got You Under My Skin." As Archer would say, "Phrasing!"

Karen heads back to her cell for the evening and of course catches the attention of new walker Patrick in the showers. Although she makes it through the night, Patrick makes quick work of one of the unnamed Woodbury transplants in his cell without waking anyone up ALL NIGHT.

In the morning, as if nothing is wrong, Glenn and Maggie share an adorable moment while keeping watch up in the tower. Luckily for Maggie, she doesn't have to worry about anyone tagging any unflattering pictures of her online.

Michonne is about to set off to find the Governor once again as Carl and Rick are getting the farm day started. She asks why Carl doesn't wear his Sheriff's hat anymore, and he says "It's not a farming hat." But, it's clear that Carl wants to be back on walker duty. Just after Carl asks his father when he can have his gun back, we hear shots come from inside the prison.

Chaos ensues. Michonne races back to help out but falls down and injures her leg while fighting off walkers. She nearly gets bitten before Carl grabs a gun and fires off the perfect shot to save her. His face turns to that of a kid who just went from playing Farmville to Grand Theft Auto V.

Inside the prison, everyone works quickly to take care of the recently turned. Daryl swoops in with a crying child in one arm and a cross bow in the other, looking badass. More unnamed survivors perish, but most notably bitten is Ryan Samuels, father of little Mika and older daughter Lizzie. Carol tries to amputate his limb but realizes he is too far gone. He asks her to take care of his daughters as if they're her own, and she obliges, but not before bringing them in to say goodbye and ALLOWING/PRESSURING LIZZIE TO STAB HER DAD IN THE HEAD. OK, we know that Carol is all about knife education, and there is a theme on this show of "being the one to do it" when the time comes, but wow. It's no wonder that Lizzie backs out, and Carol ends up doing it.

Just when you're thinking, "How/when will they figure out what the sickness is?" we see Rick, Hershel and the gang discover Patrick's body and another person who died in his cell overnight without being bitten. Conveniently, there is a new character, an Indian doctor named Dr. Subramanian or Dr S., who has survived long enough to not only diagnose the illness as a type of swine Flu (hey, remember 2009?) but break down the symptoms into a disgustingly simple soda can analogy that everyone can understand.

After Rick tells Maggie, Michonne and Carl what happened inside the prison, the "council" meets in the library to decide how to proceed. They decide to open up cell block A (or Death Row) to separate people who may have been infected.

Speaking of being infected, the council jumps up when they hear Karen coughing in the hallway, lead by Tyreese. She says another survivor named David has been showing symptoms as well, but she's clearly a goner. If it wasn't clear from her cough, it was by the looks on Sasha and Carol's faces when someone asked if she's going to be okay.

Back outside, Carol tries to confront Lizzie about why she chickened out of putting her father out of his misery. You know, because the girl hasn't been psychologically tormented enough for one day. Lizzie is distraught, but she says it's because someone killed "Nick," the walker with a name tag that she liked in the last episode. By now it looks like Lizzie is the person who has been feeding rats to the walkers, since she's the only person who might still think of them as human. And, as her little sister says, "She's messed up. She's not weak." I'm inclined to agree.

Around the other side of the prison, Daryl is burying bodies and pleading with Rick to "help us figure this out" by being a leader again. Rick says he's made too many mistakes in the past, and would prefer to help with "whatever else this place needs." Um, news flash Rick: this place needs people who can help prevent death, not grow tomatoes.

As if to prove Daryl's point, the second emergency of the episode unfolds. The horde is caving in the perimeter fence (right around the area that happens to have a pile of rat carcasses in front of it). It really looks as though the fence is going to collapse, until Rick looks over at his farm and finally says, "I know what to do."

Oh yeah, and Tyreese? This one goes out to you:

The episode gets broken up a bit during this very risky attack on the prison. While Rick and the gang tend to the fence, Michonne has an emotional scene inside with Hershel's teen daughter (and surrogate mother of the prison) Beth. She wraps Michonne's ankle and starts talking about people you care about getting hurt, mothers losing children and other totally uplifting conversation topics. Michonne is visibly uncomfortable hearing baby Judith cry, and when Beth hands her the baby abruptly, she only reluctantly takes her. Side note, this is probably my favorite shot of Michonne, ever:

It's awkward at first, but then she starts crying! And it's really sad! Did Michonne lose a child? I want to know more... But wait, let's stop and have a boring scene so that Carol and Carl can tie up that loose "knife class" end from last week's episode. It seems pretty unimportant when there's a deadly virus and major fence collapse in play. She obviously doesn't want Carl to tell Rick or the parents about them. Then again, a parent just died. Will the others really care?

Back outside, the action comes to a heartbreaking end. The piglets that were going to be eventually slaughtered by oh, dear God not like this, are wounded and fed to the walkers to lead them away from the fence.

Unfortunately, that is not even the most horrifying event of "Infected." It's hard to talk about the final scene with Rick and Carl without adressing the very end, in which Tyreese discovers that Karen, and presumably the "David" she mentioned earlier, have been killed and set on fire in a desperate act of quarantine.

The next time we see Rick, he is preparing to burn the pig pen with gasoline. Before doing so, he returns his son's gun, straps on his six-shooter holster and tells Carl that he won't stop Carol from teaching the kids how to kill. He also strongly affirms Carl saying that they "have to protect" baby Judy, even if it means doing things they don't like.

Did Rick really just take it upon himself to burn two non-walkers? That seems like something that the Governor would do. If that weren't alarming enough, we don't know how fast the virus is spreading or if it's even containable. In the end, Rick's paranoia could be more deadly to the survivors than the flu.

"The Walking Dead" airs Sundays, 9 p.m. ET on AMC.