Eighteen-year-old Gilbert Quercy has tried to commit suicide and has been sent to hospital. Nobody is surprised there when his mother comes to visit him but the nurse cannot believe her eyes when a second mother, and - even more astounding - a third one, present themselves to comfort the young patient. The reason for this is that Michel Quercy, Gilbert's father, a fanciful egyptologist always away from home, married four different women. Gilbert is the son he had with his first wife but the boy was raised by his three successive other wives after his biological mum died in childbirth. Following their conversation with Gilbert, the three "mothers" are convinced that Michel and his refusal to take his responsibilities as a father are the root of the problem. As a result, they decide to join forces in order to make the disgraceful father change his ways...