The pediatrician Waldemar Weber is in despair: his adoptive son Egon from his first marriage has announced he will be visiting, of all things, on his first wedding anniversary, although Waldemar has always kept it a secret from his young wife Henny. Waldemar absolutely has to intercept Egon. When Egon is at the door after all, he also turns out to be a monkey trainer. He also brought his chimpanzees Kiki, Koko and Kaka. Waldemar has his hands full explaining Egon's existence and hiding the chimpanzees from his suspicious wife. But is the bedroom closet really the right hiding place?