Raised alone by a single father in a lighthouse, a young girl comes to be age 11. Nemo’s father is fun and eccentric and full of imagination. One night her beloved father leaves to help a boat on the ocean and he dies at sea. He has left instructions to give custody of Nemo to her single uncle as there is no one else. The uncle is an uninspired, stodgy, uptight doorknob entrepreneur who has no clue how to raise a child and lives in a very metropolitan city where Nemo does not fit in. Thanks to a dream, Nemo discovers a secret map to the dreamworld of Slumberland, and with the help of an eccentric outlaw, she traverses dreams and flees nightmares in an attempt to see her late father again who was lost at sea.