Faut ce qu'il faut 78 years old

In 1939, in a maternity ward, a young man visits his mistress who has just given birth to a little girl. He tells her that he is married and that for him the outcome of this adventure was not really planned. The mobilization separates them but the young man will end up divorcing and with the relentless help of a friend, will find his mistress and his child and will be able to marry her in spite of the chaos of the war.