A year after the Gnome King's defeat, a new villain has arisen to take control of Oz. To do so, she has stolen the throne from Oz's next heir and the only hope is for everyone is Dorothy, along with her friends; Tom, Jerry, and Toto; who must get the rightful ruler back on the throne and at the same time, keep her from losing her head.

Patch picks out The Wizard of Oz to have a movie night with Robyn, Tom, Jerry, and Peep. However, it becomes a strange night when they find themselves in the world of the movie which includes Tom and Jerry's ancestors who had belonged to Dorothy Gale in the time of the movie and they go on an adventure after ending up in Oz to make it back home.