When students Alex (David Ladd - A Day of Flanders) and Patricia (Sharon Gurney - Jason King) discover a dying man in their local underground station, they spark off an investigation that reveals a sinister and macabre plot that even sends shivers down the spines of hardened police officers Calhoun (Donald Pleasence - Halloween, You Only Live Twice) and Rogers (Norman Rossington - Saturday Night & Sunday Morning, A Hard Day's Night). Prominent people, it seems, have been disappearing from London tube stations, and an MI5 agent (Christopher Lee - Dracula, The Lord of the Rings) is brought in to help solve the mysterious goings-on in central London. What is the terrible secret of the capital's underground system? And who - or what - is turning the London Underground into a Death Line..?
