The film is about the health resort Granhedsgården in Dalarna, Sweden, and they have a problem. They don't have many guests at all and something must be done. At the same time, Stig-Helmer is a little depressed after his girlfriend has left him, and so he lives on junk food. His best friend Ole invites him to come along to the health resort Granhedsgården. Now, the craziness begins.

The landlubber Stig-Helmer and his Norwegian friend Ole get on a barge by mistake. They arrive at an archipelago and have to spend Midsummer among the fancy rich boat people, their yachts and summer houses.

Pippi Longstocking is an extraordinary little girl who lives alone in her house, while her father sails the seven seas. Pippi's irrepressibly fun nature makes her easy to befriend, as neighbors Tommy and Annika find, but can also earn ire, especially from social worker Mrs. Prysselius.