Jacques Deray decided to put every one in an uncomfortable feeling during the shooting, especially Lino Ventura, giving him the lines to learn without explanation, on purpose, to help everyone in the crew to immerse into the complexity and mystery of the intrigue. Ventura rarely spoke to anyone between scenes, glued to his character, a man prisoner of a spider's web, but at the end of the shooting he claimed that the experience was real fun for him. Jacques Deray was surprised by this.