Roland Fériaud (Lino Ventura), on returning from a seaside vacation, discovers a corpse in a room adjoining his. He is abducted by a mysterious group who take him to a clinic of some kind, where he is interrogated. He is shown a small suitcase he has never seen before, and he tries in vain to understand what it is his captors want. Director Jacques Deray specialized in this kind of thriller, which is a typical specimen of the genre. At this time Lino Ventura was at the peak of his stardom, playing silent, stoical heros after the manner of Jean Gabin.
by Clarke Fountain synopsis