Note: This episode is an hour-long crossover between Adventure Time with Finn and Jake and The amazing world of Gumball
Princess Bubblegum has just finished on a portal machine that she needs to make. She gives it to Finn and Jake to have them watch over it while she has a meeting at her castle. She tells them not to use it but they irresponsably use it anyway. Meanwhile in Gumballs Amazing World, Richard has to leave and go to work and leaves his jucky underwaer at home and tells Gumball not to touch his underwear but he does. Thinking his dad wont notice, he rips a hole in it and doesnt know what to do!!! Just then Finn and Jake appera in his house through a portal and yap to him and he yaps back then they have an idea on how to help him with his underwear which is call Benson. Benson is there and he is trying to make things look nice then Mordecai and Rigby crash the cart through the wall because of a crazy world end going on over there. Finn dresses up as gumball to help him with his problem so Richard doesn't get suspicious.