The movie is the story of three women who set sail from a yacht club at Lake Balaton for a pleasant-seeming cruise, taking advantage of a promising day. Two of them are siblings, and the third one is the friend of the younger girl, and -not incidentally- their future mother-in-law. The older sister does not have a clue about it. The cruise begins idyllically, they sail to the middle of the lake in the mild wind, where it falls dead, and so they decide to enjoy the serenity of the autumnal Balaton. The weather is beautiful, so two of them go sunbathing on board, during which the third girl starts having fun with a fishing rod. While sunbathing they break champagne and amid great laughter they start an associative play, but for Anikó, the elder sister it is getting more and more difficult to restrain her bitter and mocking nature. From time to time, as the game advances and becomes more and more evil, the curtain gets lifted for a freezing moment, and we get to see the real relations and problems. Slowly, the cloudy relationship of the three girls, their past of lies and secrecy, and the dramatic consequences concluding from it get revealed. Everybody arrived to the boat with secret purposes, and as time goes by, and we advance in the story, it is getting more and more obvious that the tragedy is inevitable. On this beautiful day all their lives slip off the track, and change irrevocably. Eventually the elder sister is the one who can not accept the change, and makes the fatal decision. She reveals a last bottle of champagne and after a bitterly witty toast she gracefully falls into the water. The girls try to stop the boat and find her, but they can not. The two girls standing onboard scan the infinite water, and the camera slowly diverges from the boat.