When a government official disappears in the London tunnels, after several reports of missing people in the same location, Scotland Yard start to take the matter seriously, along with a couple who stumble into a victim by accident.

Donald Pleasenceas Inspector Calhoun
Norman Rossingtonas Det.Sgt. Rogers
David Laddas Alex Campbell
Sharon Gurneyas Patricia Wilson
Clive Swiftas Inspector Richardson
James Cossinsas James Manfred O.BE.
Alex Thomson