Boxer is the king of the prison. Nothing happens without him in "his" prison, and if he has to, he will even knock out a much younger inmate - at over 80 years of age, mind you. However, his advanced age is increasingly taking its toll, which has not gone unnoticed by the prison doctor. Boxer is to be transferred to a prison especially for senior citizens - the idea alone makes the sprightly prison veteran shudder. But then his buddy Henne tells him that he has been looking for Boxer's great love Kathrin, and what's more: he has learned that Kathrin has a daughter - and she looks remarkably like Boxer...