The other penguins believe Skipper has become a zombie after breaking his wing.
The penguins are all up in a tree using fishing poles to get various items from the hot-dog cart. Skipper goes for the sauerkraut, but when the hot dog cart guy closes the cart his fishing line gets trapped and pulls him out of the tree and he hits every branch on the way down. His flipper ends up broken. He tries to play it off as if it isn't broken and takes part in a number of activities that involve using his flipper such as volleyball, an arm wrestling tournament and high five practice.
Alice eventually finds Skipper with his broken wing and takes him to the vet. The vet by now is aware that Skipper is afraid of needles, and uses a topical cream on Skipper's wing that has a muscle relaxant in it, resulting in Skipper's actions being slow, stumbling and his vision being slightly blurred. When the vet leaves, Skipper promptly tries to escape through an open window and ends up accidentally turning on a hospital soap opera.
The other penguins are on their way to rescue Skipper, but when they get to the base of the window they are one penguin too short to get in. The show playing is an emergency room style soap opera and the characters in it are discussing a patient they are losing due to an infection that has reached the brain. Private is close enough to hear the show, and relates it to Rico and Kowalski. The penguins think that it is real and that they are talking about Skipper. Meanwhile, Skipper is still trying to escape and flips over a container of white powder and gets wrapped up in falling bandages.
The other penguins go back to the habitat to mourn the loss of Skipper, all of them terribly upset, and are all crying when Skipper busts through the door looking like a zombie. The penguins put on helmets to protect their brains and run away from Skipper. They run all around the zoo trying to avoid him. They are all in a garbage can when Skipper pops out and lands on Rico with his beak on Rico's head making it look like he is eating Rico's brains - and infuriating Kowalski, who screams that it should be his brain Skipper wants to eat.
Kowalski comes up with the plan that the best way to cure "zombie" Skipper would be to capture him and conduct a gruelling series of increasing painful tests to every part of his body. Skipper finally realizes he looks like a zombie to the others and tries to get away from them. Skipper bumps into Rico and makes him eventually regurgitate a grappling hook in order to make his getaway. The penguins follow him up on the roof and surround him, and are about to capture him when he finally forces himself to be able to talk normally and tell them to stop. He explains the situation to them and tries to reassure them that broken wings are not contagious.
Not believing him, Kowalski orders them to attack, and they all try to grab him and they all fall off the roof and end up at the doctor's office with broken wings. Skipper reluctantly admits that it seems broken wings are contagious - but he most certainly wasn't a zombie.