This week on "The Walking Dead," the infection that's plagued the prison has spread, killing off nameless extras left and right. In fact, things got so bad that even some of the regulars have come down with this virulent strain of the Spanish flu! Plus, thousands and thousands of Walkers attacked, and Tyreese went nuts. Here are all the biggest moments from the "Isolation" episode. (Spoilers ahead.)

Tyreese Vs. Rick
Tyreese, anguished and enraged that his girlfriend Karen (and David! Don't forget about David!) was killed and burned to a crisp, demands Rick find her murderer. Rick tries to calm him down. Tyreese proceeds to sucker-punch Rick, only to get sucker-punched by Rick, who then beats the sh-- out of him. They patch things up (sort of) by the end of the episode, but even in a show that doesn't shy away from violence, that fight was brutal.

Glenn Gets Sick
First, Glenn gets the sweats. Then Maggie discovers him hunched over a sink in the prison, and he tells Maggie, "I have it." Cut to commercial. The story line wasn't just there to test Maggie and Glenn's resolve though; it also showed how far Maggie's dad Hershel and Glenn have come. Hopefully this plot twist won't kill off the fan favorite, but it seems like no one is safe....

Mossy The Walker
This is a little moment, but Carl and Hershel are out in the woods picking herbs to soothe the infected — which is, of course, something a veterinarian would know how to do since dogs love drinking tea — and discover a nearly decayed Walker covered in moss. The mix of natural serenity and gross deadness the show does so well is perfectly encapsulated in this image and has created another classic done-in Walker.

Hershel's Big Speech
This was overall a big episode for our favorite one-legged vet, but it crested in two moments. First, he's confronted by Maggie and Rick, who don't want him to enter the infected wing of the prison. Hershel delivers a great speech about how they all risk their lives every day, and if he has to go out, he wants to do it knowing he did something to help the sick. Then later on, he straight up has blood coughed on his face by Dr. S, sighs, wipes it off, and matter-of-factly removes his "protective" bandanna. After literally seasons of Hershel just being there as advisor to Rick and others, it was great to see him step up and take action.

Bicycle Wheel Walker Distractor!
Sure, Carol getting trapped outside the fence while fixing the water supply was plenty tense, but we couldn't stop watching the rotating bicycle-wheel Walker-distracting mobile the gang has built. It makes noise and constantly rotates, so it draws the Walker's attention. Genius!

Daryl Knows What Michonne Did Last Summer
They still haven't said the name "Governor" yet this season, but at least someone knows what Michonne's been up to: scouring the countryside for the eye-patched villain. In a brief conversation in a car (and side note: if you're not shipping Michonne and Daryl after this episode, you're not watching the same show we are), Daryl tells Michonne the trail has gone cold and she should stop looking. Yeah, right. Just a subtle reminder that he's still out there, and we may finally get the confrontation we all wanted from last season.

Radio
No, not the Cuba Gooding Jr. movie. As Daryl drives, he's distracted when a message is broadcast on the radio! We've seen this play out on the show before, but hey, someone is out there, and we imagine we'll find out who soon.

7,500 Walkers Makes It A Party
... And just as Daryl is distracted by the radio, the car crashes into a horde of 7,500 Walkers, leading to a HUGE action sequence. Daryl, Michonne and Poochie — sorry, Bob Stookey — blast their way out of the pack, while Tyreese sits in the car deciding whether he wants to die.

Hammer Time
Luckily, Tyreese doesn't just sit in the car and slowly succumb to the inevitability of mortality. Instead, he pulls out his frickin' hammer and goes to town on all the zombies, shouting, "Come on and kill me," as he bashes in Walker head after Walker head.

Carol Killed Karen
And David! Carol killed David too! Earlier in the episode, Rick put on his detective hat for about three seconds before figuring out Carol had exactly the right size hand to make a bloody print on the door outside the yard where Karen and David were burned. He confronts her, and she doesn't even hesitate to tell him that she killed the duo in order to try to stop the spread of the infection. Given that Daryl swore he'd put a bullet in the head of whoever committed the deed, things do not look good for Carol/Daryl shippers. Hey, maybe we can just switch over to Michonne/Daryl and everything will be fine? Yipes.

What did you think of the latest episode of "The Walking Dead"? Let us know in the comments below!