Margaret is transferring to another college, so Mordecai, Rigby and Eileen plan a going-away party at the park's abandoned ballroom, still haunted by its past hosts.
Mordecai and Rigby buy a potentially deadly sandwich at a restaurant, but when Benson falls ill after he eats it himself, they must set out to find the cure before he dies.
While camping out in a cave, Mordecai and Rigby accidentally melt a caveman frozen in a block of ice. When they try to keep him, Benson requires that they make him more civilized.
Mordecai and Rigby help their favorite '80s sitcom star, RGB2, escape from the studio lot and into the mountains to get out of a contract that has trapped him into staying on the show.
Muscleman, Mordecai and Rigby help "Donny G", a famous D.J. take back over the corrupt local radio station so Muscleman can play his song he wrote for Starla on the radio.
Mordecai, still in a state of depression from Margaret's rejection at the Stake Me Amadeus restaurant, ends up finding her sweater in the laundry and plans to give it back to her at her college.
Mordecai and Rigby decide to create songs and sing them to people in the park so they can raise money to buy a special video game, but they run into a silver street performer who is stealing their songs and dancing to them.
Mordecai, Rigby, Muscleman, and High-Five Ghost want to eat an Every Meat burrito, but the restaurant won't let them buy any until they have an actual car to use in the drive-through.
When Pops gives Tants, the table-pants, to Mordecai an Rigby as a gift, they accidentally ruin them and have to get new ones before their "Tants-Lunch" with Pops the next day.
Mordecai, Rigby, High-Five Ghost and Muscleman have to get a stuntman license, so they can perform at a little kids birthday, when the original stuntman cops-out at the last minute.