Gary Sherman (Dead and Buried) churned out this gory, slower paced Brit-Mystery Horror at the early part of the 70's, about the legendary subway killer.
Two college hipsters find an unconscious British politician on a set of subway stairs. They argue wether to get involved and telling the authorities, upon returning to the knocked out/possibly drunk politician they find he is gone. Enter Inspector Calhoun (Donald Pleasance aka Dr. Loomis), half comedian half rule breaking detective, the couple's complaint creates more questions concerning other "missing" cases related to the underground subway tunnels. Brief (and I mean brief) cameo by the always pleasant Christopher as an opposing agent to Dr. Calhoun adds little to the detective part of the story, but if you are a Lee fan, he is still cool as shit.
The films pacing is undiliberatley slow and slightly off putting from mildly warm scenes between Pleasance and others within his office to the overly gritty subway cannibal family and their grimy way of life. Sharon Gurney, the love interest of the films protagonist played by David Ladd, is easy on the eyes in contrast to the grotesque and convincing make-up of the main, constant drooling, Cannibal (Hugh Armstrong) and his relentless rephrashing of "Mind the Doors!"
One particular stand out long, long, long camera shot reveals the interior of the Cannibal's dwelling and the tunnels connecting to the busy subway, adding needed tension and showing Gary Sherman's early eye for suspenseful layout's.
I would only recommend this for Pleasance/Lee or Sherman completists. The film is at best, a mediocre gross-out detective story. Similar plots can be found in the much superior Frightmare by Pete Walker.