Adventure Time Season 8 Episode 22 - Islands Part 3: Mysterious Island Episode Title:Islands Part 3: Mysterious Island.Episode Description:After an encounter with a colossus, Finn wakes up on an island where the weather drastically fluctuates. He encounters an old lady named Alva (voiced by Helena Mattsson) who does not speak English. Alva invites Finn to her home and shows her home movies of other humans who have presumably died. Later Finn, Alva and her pet bear encounter Jake who does not know the whereabouts of BMO and Susan. On the moon, BMO is being attended to by another robot and wishes that Finn, Jake and Susan could join her.