In 16th century Italy, on the Adriatic coast, the duchy of Doruzza is governed by a tyrannical duke, Zulian, and his haughty daughter, Isabella. When they commit a great injustice, a ship's captain and his daughter turn pirate to fight back for the people.

The summer holidays have just begun in Brandenburg, but ten-year-old Lea isn’t going to camp this year with her friends as she normally would. One afternoon she spots five boys lifting a large blue oil barrel over the fence of a paint factory and driving away with their loot on a bicycle trailer. Lea's curiosity is piqued. The next chance she gets, she follows the boys and discovers they built a raft on a small lake. The raft is the boys' property and under no circumstances girls are allowed in their gang. But Lea wants to be part of it very badly and takes them up on a dare. Soon summer is full of adventure.