The night doctor Jakob Man is called out to the wealthy director Holm, whose young wife Kirsten apparently has fallen down the stairs. A short while later he is contacted by Kirstens mysterious girlfriend, who wants help. Slowly the doctor is caught in a diabolical plot.

Jakob Man is accused of a murder, which he has no idea if he committed. But everything points towards him and he is convicted. After several years in prison he is out again, when he slowly realises what actually happened and he plans his revenge with compound interest.