"Sick" is the second episode of the third season of AMC's The Walking Dead. It is the twenty-first episode of the series overall. It premiered on October 21, 2012. It was written by Nichole Beattie and directed by Billy Gierhart.
After the traumatic event of Hershel losing his leg after he was bitten, the prisoners that have been hiding out in the broom closet of the cafeteria come out, noticeably uneducated about the apocalypse. They mention that they had been locked in the broom closet when 'riots' broke out by one of the guards, Tomas being given a pistol to protect the five. Rick and company initially leave the prisoners be, taking Hershel back to Cell Block C. Upon leaving Hershel to Glenn and the rest, Daryl points his crossbow at the corridor as he sees the prisoners following them. A standoff occurs, and soon Rick intervenes. The eight of them go outside, the prisoners are in disbelief over Rick's group being able to kill "at least 50 bodies." They also show they'd never known that only the damage and/or destruction to the brain will kill a walker, as well as the fact that a bite is not needed to turn.
Soon, Tomas begins demanding that the prisoners be let back into Cell Block C, due to their having been in the prison longer. Rick instead demands that Tomas' group abstain. Soon, Axel begins to propose a compromise of moving into a different cell block. Rick and Tomas eventually make a deal: In exchange for half of the prisoners' food supplies, Rick, T-Dog, and Daryl shall help clear out a different cell block. First, Rick and company take half of the supplies back to Cell Block C. The group of eight then begins to go over what they have to fight with. In the beginning of the clearing, Rick uses a signal to attack but the prisoners stormed ahead, attacked with poor fighting technique against the walkers, focusing more on the torso than the head. However, they eventually get in the habit of striking the brain. In the middle of fighting, however, Big Tiny tries to retreat but ends up being scratched in the back of his shoulder, a part that couldn't be amputated. A short argument ensues over what to do with him, only to be interrupted abruptly when Tomas savagely kills Big Tiny.
Meanwhile, Maggie, Beth and Glenn are busy trying to assist Hershel. Glenn had been put to the task of making sure Hershel doesn't come back if he doesn't make it. Glenn frequently tries to convince Maggie to be prepared, and Maggie tries to convince Beth to not get her hopes up. Carl, having been assigned to organizing the food, instead, he returns with a small amount of medical supplies that he obtained from the infirmary - a risky move to go on his own. He claims that he killed two walkers, which only worries Lori. Soon, the argument leads to Carl bluntly telling his mother to "get off his back." The women notice this, looking at Carl. Before he leaves, Lori gives one last comment of praise for finding the desperately needed supplies.
Rick and Daryl have agreed to kill Tomas given the first wrong move. Arriving near the destination cell block, Rick tells Tomas to open only one of the double doors. However, Tomas doesn't listen, instead opening both doors at once, resulting in the walkers pouring into the room. During the fighting, Tomas takes a swing at a walker, killing it but in the process takes another swing at Rick. Tomas then pushes a walker into Rick, attempting to get him killed. Daryl, fortunately, steps in and kills it. Within moments, the walkers are all killed, and a short discussion leads to Rick splitting Tomas' head with his machete. Andrew retaliates by attacking with his baseball bat, only to be knocked down easily. He then runs into the corridor, which has now been cleared, leading to Rick pursuing, leaving Daryl and T-Dog to watch Oscar and Axel.
After Rick ends up chasing Andrew into an enclosed yard of walkers, he shuts and locks the barred gate behind Andrew, leaving him inside of the space. Andrew pleads with Rick to let him in, but Rick coldly refuses. He closes the inside door behind him, and all that is heard from Andrew is screams of terror.
Carol requests that Glenn come with her outside. She reveals that she wishes to select a female walker to practice a C-Section on, knowing that if Hershel even survives, he won't be able to help Lori deliver the baby, and that she'll probably have to perform a C-Section on Lori due to Carl having been born that way. Glenn distracts the rest of the walkers, giving Carol time to drag the female walker in. As Carol begins her dissection of the female walker, someone is watching her from the woods.
Maggie sits with Hershel to watch him as he sleeps, after a few minutes she finds that he's stopped breathing. Lori then performs a successful CPR on him.
Rick then comes back to Axel, Oscar, T-Dog and Daryl, threatening to kill the former pair. Axel pleads that he and Oscar aren't violent like Tomas was, begging that they be left alive. The three then turn to Oscar, who refuses to beg or plead. Rick realizes that Axel's words are true, and leaves the pair to the now cleared-out cell block. Axel shows deep sorrow at the sight of his fellow prisoners laying right outside of their cells, executed, only hearing T-Dog's final suggestion of taking the bodies out and burning them.
Upon returning to their group, Rick, T-Dog, and Daryl find a now-unresponsive Hershel inside the crowd. Sitting alongside Hershel, they eagerly await the man's fate. Hershel's eyes open, to which Maggie and Beth begin to cry tears of relief.
Lori and Rick begin to talk on one of the fenced-in catwalks outside. Rick says they'll begin to clean out the bodies the next day, which Lori responds by saying it'll give Carl space to do "whatever he does these days." Lori says that today was a good day. Rick tells her he doesn't think she's a bad mother, to which Lori replies, "Wife is a different story." Rick touches her on the shoulder, which almost brings her to tears. Rick tells Lori that the group is grateful for her saving Hershel, then he walks away.
- Clair Danielle Canterbury, Gregory French , John Jaret, Don Teems, Alyssa V. Mullan, Anthony "Chopper" Rinaldo, Michael Maughon, and Tyler Capehart as Walkers
- Last appearance of Tomas.
- Last appearance of Big Tiny.
- This title of the episode, "Sick", references a comment made by Oscar after seeing dead his fellow inmates.
- This was the first episode to air on Dish Network following their agreement with AMC Networks.
- Scott Wilson often fell asleep while shooting the scenes where Hershel is unconscious.
- When Rick informs the prisoners about the apocalypse and how all societal structure has collapsed, what Rick says is very similar to what Mark and Selena tell Jim in the 2002 movie, 28 Days Later.
- There were thirty confirmed walker kills in the episode and two living humans. Rick and Tomas both tied with the most kills at five walkers and one living human.
- Hershel being treated by Carol and Lori in a cell after having his leg amputated is adapted from a similar scene in Issue 21, where Dale is treated by Alice in the infirmary instead.
- Rick, Daryl, and T-Dog killing walkers with the help of the inmates is adapted from Issue 19.
- Rick confronting the inmates and killing their leader is adapted from Issue 19.
- Andrew running away to escape is adapted from Issue 19.
- Carol requesting Glenn to bring a walker inside the prison to practice to deliver Lori's baby is adapted from a similar scene in Issue 40, where Alice requests Andrea to bring a walker to study it instead.
- When Rick and his group are returning Hershel back to the cell blocks, Rick orders Daryl to kill a walker blocking their way in the hallway. Daryl kills the walker with an arrow from his crossbow and as he moves past the walker, he pulls the arrow he fired out of its head, however, Daryl is holding the tail end of the arrow instead of the front-end after he pulled his arrow out which is logically wrong.
- When Carol kills the female walker with the metal pipe. There is blood on the pipe where she stabs it, but when it's removed and she tells Glenn to distract the other walkers. The metal pipe has no blood on it at all.