Sabine, aged 15, has an extraordinary talent for mathematics. She tries to apply her genius for logical reasoning to the rest of her life, which is not easy as her parents are constantly on the breadline and appear to resent her success at school. Whilst Sabine is collecting money from her male friends for doing their homework, she is mistaken for a prostitute by Jiri, a 40 year old Czech playwright. Sabine is grateful for the payment she receives after Jiri makes love to her but somehow she expects more. When she sees Jiri with another woman, Sabine throws her cool restraint to the wind and makes a complaint about him to the police. She soon realises she has made a mistake - but what is the solution to this complex problem...?