Crudup's Zimbardo shifts from ruthlessness to panic, but that shift isn't nearly as marked as what we observe among his subjects.

The film runs out of steam by about the half way mark, where matters of unequivocally passed through the gates of Hell.

The acting is uniformly strong and the camera work is winningly claustrophobic, but the film is one note: scene after scene of bullying.

The extent of their malicious humiliation is enough to turn blood to ice, creating a hellish arena cloaked in uniforms and aviators well beyond what one would expect your average 18-year-old capable of.