Stuart Whitman is the one who originates the first sand in the machinery, and he isn't even aware of it, but all the other actors are also surprisingly good. There are several very striking scenes when John Russell takes his accomplices under treatment, none of them having the courage to drop out of the hell bound enterprise, while one of them has to suffer badly for his just suspecting her female weakness. It's a great script with very apt music, and the characters are all convincing, especially the cold turkeys under the strain of insulin and that other stuff. Most impressive is the finale in the junk yard among the scrapped trams, the cranes and the trains, which would have provided ideal material for Hitchcock. He is missing here though, and there are no stars, while Stuart Whitman always makes good in any film.