This dark horror film from director Ulli Lommel was based on the real-life crimes of Fritz Haarman (Kurt Raab), the so-called "Vampire of Dusseldorf" who murdered over 25 young boys, drank their blood, and sold their flesh as black-market meat. Several German films had depicted Haarman's murderous exploits, most notably Fritz Lang's classic M (1931), but Lommel's version is far more graphic and horrifying. Produced by filmmaker Rainer Werner Fassbinder, who also appears, the film revels in pseudo-Expressionistic imagery which sears itself into the viewer's mind. Raab's performance is reminiscent of both Peter Lorre in M and Max Schreck in the vampire classic Nosferatu (1922), but is unforgettable in its own right. A deeply disturbing cinematic poem about the face of true evil, this overlooked classic has developed a cult following, but is not recommended for sensitive viewers.