After being friends for years, Finn and Marceline tell each other how they feel and begin dating. After messing around with magic crystals, they end up in Gotham where they meet and befriend Batman. Meanwhile, Two-Face plans to blow up half of both Gotham and Ooo so they see the world like he does. With their homes in danger, Batman teams up with Finn and Marcy to stop Two-Face.
Both Jervis Tetch and Alice Pleasance decide to start new lives as far as Jervis reforming from crime, and Alice divorcing her husband after he cheats on her. Evenually the former friends run into each other once more which causes them to rekindle their friendship and that eventually leads to them falling in love and living in the Wonderland they have both always searched for.