Season synopsis
Contains spoilers for this season and earlier seasons.
Finn and Jake’s second season begins when Finn tries to help Marceline record a song about her estranged father. He summons her father from the Nightosphere without understanding that the demon consumes souls; after taking Marceline’s bass, her father rampages through Ooo and traps its inhabitants’ souls. Finn plays back Marceline’s song, the two reconcile, and Finn frees the souls before banishing him. Elsewhere, the boys protect three mysterious pods and enter the Land of the Dead to retrieve the soul of Bubblegum’s dead plant. There, Jake loses his memory and Finn loses a musical duel against Death. They narrowly escape, and later meet Susan Strong, whose apparently human underground community excites Finn’s hopes of finding others like himself.
An escaped Lich threatens Ooo, while Ice King keeps interrupting Finn and Jake’s pursuit to demand permission to marry Bubblegum. Finn defeats the Lich with the sweater she gave him, whose protective power lets him resist the creature’s mind control. But Ice King drops Bubblegum into the Lich’s well of power, and she returns possessed. The boys reluctantly join Ice King to stop her. He freezes Bubblegum, who falls and shatters; her surviving pieces are reassembled into a thirteen-year-old body. The Lich survives by possessing a snail, despite the friends’ apparent victory.