Langåsen boarding school has its 50th year anniversary, and the students are to make a celebration show in the auditorium. Trouble is brewing when a school inspector is to visit the school at the same time.

Stompa has turned seventeen and has acquired interests other than innocent mischief. He falls in love with the mysterious Nel Shaiba from a traveling circus that has settled in town.

Stompa takes on the Atlantic Ocean to surprise his origins in New York. He is mustering on a 20,000-tonne ship together with his friend Nøtterø who would like to sail the seven seas during the summer holidays.