Ludwig and friends live in a world of books. One day, a postcard arrives; Ludwig's friend, Peter the penguin, has a broken submarine and needs Ludwig's help - under the sea. How can a dog who lives in a book explore the underwater world? Maybe with a bit of fairy tale magic and some help from his friends.

This is the second 3D picture book from the author of Ludwig the Space Dog. Get ready for an adventure in another dimension.

Illustrated by: Henning Löhlein