It's Time

Synopsis
Mordecai becomes extremely jealous when Rigby manages to get a date with Margaret. Mordecai tries to prevent Rigby from getting to his date on time by destroying all the clocks they have. This causes the two to be transported to another dimension; and along the way, Mordecai kills Rigby and soon regrets it. Now, Mordecai has to meet a being named Father Time, so that he can go back in time to set things right.

Plot
Mordecai and Rigby watch a preview of "Zombie Dinner Party", a new film about zombies killing people, at Margaret's restaurant. Rigby has two tickets to see it, while Mordecai, has two tickets to go see "Pajama Sisters 2", a film about girls expressing their feelings. Rigby does not want to see that, complaining "it's just girls expressing their feelings, fully clothed." However Mordecai still wants to view it. Mordecai hesitates asking Margaret if she would like to come with Mordecai to see "Pajama Sisters 2" with him, as usual.

However Rigby interrupts and makes a joke causing Margaret to laugh, much to Mordecai's jealousy. As Margaret brings their food, she ends up bringing the wrong order for Rigby, due to her being stressed out about her moving that day. Mordecai offers to help her, as well as Rigby, who makes another joke causing Margaret laugh once again. Mordecai gets angry and kicks Rigby in the leg, signifying even more jealousy.

As they load the boxes into Margaret's car, Mordecai struggles to tell her about the tickets, but yet again, he still hesitates. Rigby once again, makes another joke turning Mordecai even more jealous. Rigby asks Margaret to see "Zombie Dinner Party" with him and she accepts, making Mordecai furious.

Later Rigby continues to taunt Mordecai about his date with Margaret with Muscle Man, and beating him in a fighting video game, making his player save the girl and make out with her, which Rigby intends to do with Margaret. Soon after, Mordecai is seen sitting in front of a TV screen with static. Mordecai shows Rigby that there is no battery in the watch Rigby had been wearing. Mordecai then takes all the clocks in the house (while being chased by Rigby) and puts them in a microwave to boil them, so that Rigby won't know what time his date with Margaret is. However, this action causes Mordecai, Rigby, and the microwave to go to another dimension with resembles the background in the intro.

They fight about the date with Margaret. Mordecai said that Rigby "had to butt in" and steal Mordecai's crush. Rigby retaliates by saying that he was dumped for some girl who doesn't know Mordecai exists. Deeply hurt, it gets out of hand as Mordecai screams "I'll kill you!" and pushes Rigby off the microwave, instantly incinerating him. Mordecai, shocked at what he's done, is taken to a flat surface. He finds invisible furniture and an invisible door. Father Time, an entity made out entirely of clocks talks to Mordecai about what he's done, including being jealous, and burning all of his clocks. Mordecai apologizes for what he's done, even admitting himself that he was jealous. Father Time accepts his apology and tells Mordecai that if he ever does this again, he will be sorry. He tells Mordecai to ride the "time pony" back in time.

Mordecai hops on the "time pony," which is invisible. This is met by Father Time's comment that "Is that how you ride a time pony?... It's just weird, is all." We then see the invisible pony fly forward, and Mordecai backward, while seeing the process of going back in time. Mordecai goes back to the beginning of the episode when Rigby tells Mordecai that he has tickets to "Zombie Dinner Party." Mordecai agrees to go this time, and then tries unsuccessfully to make a joke for Margaret. Rigby interrupts once again, and makes his joke, causing her to laugh again. Rigby sees Mordecai is jealous. Mordecai denies this, but then states he's a "maybe just a little bit" jealous.