This is one of the finest detective mysteries ever filmed. It is astonishing that the young director Don Siegel showed so much talent so early. Once again we have that wonderful pair, Sydney Greenstreet and Peter Lorre making a masterpiece together. Greenstreet is spellbinding in every scene. Lorre creates a well-rounded three-dimensional character from a two-dimensional part, and makes him eccentric and intriguing. The story is set in 1890 in London, and is based on a novel entitled 'The Big Bow Mystery' by best-selling author Israel Zangwill, which was in turn apparently based on a real case. The plot of the film is one of the most complex and intellectually challenging ever made. It 'out-Sherlocks Sherlock'. The essence of the dilemma is how can a man have his throat cut in a room in which the door and windows are locked and bolted from the inside, and there is no other way in or out. The film is helped a lot by a brilliant performance by Rosalind Ivan as a hysterical landlady who may or may not have murdered her lodger (but how??). The atmosphere is powerful, the filming expressionistic, the style impeccable, and the result magnificent. Greenstreet and Lorre are at the top of their form. This is a film no lover of the genre should miss.