 A 40-year-old mechanic whistles at a passing teenager; she stops and upbraids him. In embarrassment, he claims he was whistling at her companion, her 14-year-old cousin, Isabelle. This changes Isabelle s outlook on life: her favorite story is Anderson s "Little Mermaid," and she thinks that in Georges she s found her prince. She follows him, engages him in conversation, and turns up at his flat. At first, he pushes her away and tells her she s nuts, but slowly he finds that she brings out of him a playful self, and he likes her devotion. The attraction builds, threatening Georges  adult relationships, including that with Nelly, his sweetheart. Where on earth can this affair lead?