A sailing boat approaches a small island in the Stockholm archipelago. When Kalle, the master of the boat, tries to dock it alongside the wharf, Walter, one of the passengers, happens to start the motor, whereby the boat goes backwards out on sea. A series of attempts to bring the boat to the wharf fail. Kalle, Walter and Mona have to stay aboard, 100 meters from the shore, while the 4th passenger, the businessman Olsson, drifts away on a loose part of the wharf. Kalle's wife Berit and Mona's husband Lennart have prepared a crayfish party at the porch of a summer cottage close to the wharf. After failing to help the boat passengers to get ashore, Berit, Lennart and Berit's mother Inez start the party themselves. There is one more inhabitant on the island, the fisherman Garbo, but he refuses to let the summer guests lend his rowboat. A plan to steal his keys to the lock of the boat fails, and the angry fisherman locks them up in the summer cottage, and then destroys his rowboat. After several more unsuccessful attempts to reach the shore, the sailing boat finally crushes into the wharf. Now no one can leave the island.
—Maths Jesperson {maths.jesperson1@comhem.se}