Fisherman Ärni has decided to take vacationers for midsummer due to the poor catch of fish. The plan is not bad, but extremely troublesome guests arrive at his beautiful farm in Muhumaa: Mrs. Sohvia, her husband Johan, their son Junior and Sohvia's beautiful sister Erna with her businessman cavalier Ivo. From first glance, it is clear that Ärni and his wife Laine will have a hard time with these vacationers.