Petite but agile eighty-two-year-old Maria Schmidleitner is going to spend some time on a houseboat in rural Brandenburg with her obese son Peter (63). As they are in the car on the motorway on their way to the boat Peter insists on picking up a young hitchhiker against his mother’s wishes, but when the young man only exacerbates the perennial mother-and-son conflict he is quickly dropped off again. No sooner are they on board the houseboat than Mum turns her son’s afflictions into her weapon and drives Peter crazy with her constant questions about his blood pressure and glucose levels. But all Peter wants is her love. His late coming out, her sentimental memories of Hitler and their constant arguments, but also their affection for each other come to an abrupt end when the boat’s motor conks out.