Winner of the Silver 2022 ENNIE Award for Best Adventure

A kidnapping. A map. A lost U-boat.

There is something fishy going on in Paris. The kidnapping of journalist Pierre Martin seems to be connected to a marine expedition to the island kingdom Sitomeyang on the other side of the globe. Clues point to the mysterious organization The Octopus, whose tentacles reaches everywhere.

Only a band of intrepid troubleshooters can find out how all of this is connected and solve the U-Boat Mystery.

The PDF version of The U-Boat Mystery is included and can be retrieved by a unique code included inside the book.

An exciting adventure which takes you from Paris to a lost U-boat on the other side of the world!

Can the adventurers figure out who is behind the kidnapping, and find the secret of the lost U-boat from WW2?