Struggling to find his place as a human in a magical world, Simon considers taking desperate measures before embarking on a quest with an old friend.

Fionna, Cake, and Simon converge in a strange place to discover how they're connected.

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.

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