It is a dystopian story about an English detective named Fisher (Michael Elphick) who has become an expatriate living in Cairo. Fisher undergoes hypnosis in order to recall his last case, in which he pursued an elusive killer called the "Lotto Murderer", who brutally savaged young girls selling lottery tickets. Fisher had attempted to track down the killer using the controversial methods outlined in a book titled The Element of Crime, written by his disgraced mentor, Osbourne (Esmond Knight). Fisher is joined in his search by a prostitute named Kim (Meme Lai).
There are a number of visual motifs that distinguish the film. It is always shot at night, and it is usually raining — water figures as a prominent element in virtually all of the film's scenes. (This has led some critics of the film to draw unfavorable comparisons to Ridley Scott's Blade Runner.) The film is also shot in sepia tone, which becomes more pronounced as the movie progresses to the point that some shots are awash in vivid yellows or reds; this color scheme is occasionally shockingly contrasted with blues or greens that are just as piercing. The film's pace and dark atmosphere evoke a soporific, dreamlike quality.