Other reviewers have summarized this film noir well. I just wanted to add to the "Whew!" comment one reviewer made regarding Elisha Cook's obviously coke-fuelled drumming episode. This WAS a doozy, I must say. Cook deserved some acclaim for his frenzied performance.
A bit of trivia that I am surmising about: Cook appeared as a waiter in the 1941 Barbara Stanwyck film, "Ball of Fire." He was a waiter in the nightclub where Barbara was singing and legendary drummer Gene Krupa was drumming, most energetically. Is it too much to suggest that Cook's spazzy drumming in the later film, "Phantom Lady," was very much inspired by Krupa's work, as witnessed by Cook 3 years earlier?
If you watch Krupa in "Ball of Fire," I think you'll note some clearly similar body movements. One hopes, of course, that HE was not influenced by any drugs at the time!