Pursued by a powerful enemy, Fionna, Cake and Simon venture through a lawless world in search of a magical artifact.

After landing in the Winter Kingdom, Fionna and Simon discover a possible solution to their problems. Marshall Lee helps Gary with a baking project.

Cake is recruited by a band of skilled vampire hunters. Gary and Marshall Lee attend a black-tie party.

Stranded in a desolate wasteland, Fionna, Cake and Simon must resort to desperate measures to escape.

While Simon experiences a cosmic detour, doom closes in on Fionna and Cake.

Simon battles his demons as Fionna, Cake and friends fight for their world.