Summer 1969: The Americans fly to the moon and Johanna's life gets into turmoil. While her family spends some days in Hamburg, the hostess stays alone on the secluded Hallig to accommodate a guest. The hydraulic engineer Anton Brunner will carry out the necessary investigations so that the Halligs can be supplied with fresh water from the mainland. In these summer days, Anton and Johanna fall in love with each other passionately. When her family comes back, she has to make a decision.