One of the darkest thrillers, and most innovative as well, this film is a classic suspense-thriller, verging into horror, without missing a beat. The aura of this film, or mis-en-scene, is always perfection, whether that be the bleak, underground set, the blank cinematography that captures the allure and horror of darkness, or the performances, all carried by actors who know their craft exceptionally well. The feeling of being trapped, or claustrophobic, permeates this film throughout, making you very uncomfortable and very aware of the stakes of the film. It's strange knowing the evil of the film, and the exposition, which makes the protagonist's plight that much more harrowing. The main heroine in the film is a recently blinded woman named Susie (Hepburn) who is left alone in her basement apartment by her husband to fight off several men who are looking for heroin in her apartment. The setup is so beautiful and horrific, and the way it is all explained in the first twenty minutes is encapsulating, strange since it simply involves several men talking to one another. The plot against Susie is extraordinary and yet so thrilling, because though they don't use blunt force against her, you know they could kill her in the next instant. Particularly scary is the performance from Alan Arkin as Harry Roate, described by many critics as one of the most terrifying and villainous performances onscreen. Arkin gets goofy once in a while, putting on disguises and trying to fool Susie, and that makes it a little cheesy, but otherwise this film feels perfectly thrilling from beginning to end. There's even an electrifying and heart stopping climax that will make any scaredy cat scream for their life. Just such a beautiful and shocking thriller, on so many levels.