Shortly before her wedding, Sonja meets a photographer in the botanical garden. On a whim, she tells him the love story of her youth: in the summer of 1976, 12-year-old Sonja moves to the countryside with her family. Here she meets the boy next door, a quirky outsider who everyone just calls Boiler. Sonja and Boiler share the same passion: they want to be in the movies. A tender rapprochement begins. They soon plan a joint project, an "agent film", which they shoot in the nursery's greenhouse. Nevertheless, Sonja is unable to commit herself wholeheartedly to Boiler. She denies her friendship with Boiler in front of her clique. She betrays him again and again. Finally, Sonja instigates a dangerous test of courage in which Boiler puts his life at risk...
