Hugo's daughter Rut wakes to strange noises coming from the attic. Inside she finds a dusty captain's log, and inside the log is a bookworm named Geo who tells her the story of her great-grandfather: a pirate captain who found a treasure chest — only for the treasure and the crew to be scattered by a tornado sent by the witch Scylla, sinking the ship. The chest needs three magic keys to open, and they were lost with everything else. Rut packs her bags and sets out across more than 20 locations to find all three.