Milan (Hallyday), an enigmatic, aging gangster whose next job is to hit the bank in a small, provincial French town, arrives by train, and goes in search of aspirin to ease a migraine. There, he meets Manesquier (Rochefort), an elegant, retired schoolteacher of French poetry who is as chatty and friendly as Milan is taciturn and reserved. The older man offers his new acquaintance a room in his large mansion, and the two cautiously get to know one another.
Even though they appear on the surface to be complete opposites, Milan and Manesquier find that they have many things in common. Their guarded relationship slowly turns into one of mutual respect. Both men are approaching their twilight years. Manesquier fantasizes about robbing a bank, while Milan looks around at the comforts of his host's house and wonders what it would be like to enjoy a life of ease. As the two men talk about their lives, admiring and envying each other's lifestyle, a subtle osmosis occurs.