One night, Hugo's daughter Rut is roused by strange noises. The noise comes from the attic and so Rut sets out to check. The girl makes her way there and finds a dusty captain's log. Curious, Rut opens the book and discovers an old bookworm named Geo, who tells her the story of her great-grandfather who was a pirate captain, and of a treasure chest that they found but which was then was lost after his ship was sunk and the crew dispersed by a tornado sent by the evil witch Scylla.
To open the chest, Rut will need three magic keys. And so Rut packs her bags and goes on a great voyage in a search for them, exploring a fantastic world with more than 20 locations and having many adventures.