Fionna, her best friend Cake and the former Ice King, Simon Petrikov, embark on an adventure through the multiverse, dodging new threats and making self-discoveries along the way.

Fionna and Cake--with help from the former Ice King, Simon Petrikov--embark on a multiverse-hopping adventure and journey of self-discovery. All the while, lurking in the shadows is a powerful new antagonist determined to track them down and erase them from existence.