An ageing prostitute has to deal with a customer not as the others. Her caresses do not seem to have any effect on him. She has seen others, it is her job. The stratagem which she imagines is disturbing because it supposes a blind confidence of the customer in this woman whom he knows hardly and who proposes him a secret variant intended to refresh his libido. But we discover that she interpreted with a little common intuition the enigma of her partner.