Characters played by Brian Donlevy
Quatermass
Characters played by John Longden
Lomax
Characters played by Sidney James
Jimmy Hall
Characters played by Bryan Forbes
Marsh
Characters played by William Franklyn
Brand
Characters played by Vera Day
Sheila
Characters played by Charles Lloyd Pack
Dawson
Characters played by Tom Chatto
Broadhead
Characters played by John Van Eyssen
The P.R.O.
Characters played by Percy Herbert
Gorman
Characters played by Michael Ripper
Ernie
Characters played by John Rae
McLeod
Characters played by Marianne Stone
Secretary
Characters played by Ronald Wilson
Young Man
Characters played by Jane Aird
Mrs. McLeod
Characters played by Betty Impey
Kelly
Characters played by Lloyd Lamble
Inspector
Characters played by John Stuart
Commissioner
Characters played by Gilbert Davis
Banker
Characters played by Joyce Adams
Woman M.P.
Characters played by Edwin Richfield
Peterson
Characters played by Howard Williams
Michaels
Characters played by Phillip Baird
Lab. Assistant
Characters played by Robert Raikes
Lab. Assistant
Characters played by John Fabian
Intern
Characters played by George Merritt
Super
Characters played by Arthur Blake
Constable
Characters played by Michael Balfour
Harry
Characters played by John Adams
Policeman
Characters played by Chris Adcock
Worker
Characters played by Peter Brace
Guard
Characters played by Daniel Brown
Worker
Characters played by Tony Castleton
Worker
Characters played by Leslie Crawford
Guard
Characters played by Vernon Greeves
First Man
Characters played by George Hilsdon
Guard
Characters played by Jan Holden
Young Girl
Characters played by Arthur Howell
Guard
Characters played by Alastair Hunter
Labour MP
Characters played by Barry Lowe
Chris
Characters played by Colin McKenzie
Guard
Characters played by Norman Morris
Intern
Characters played by Jim O'Brady
Guard
Characters played by Henry Rayner
Drunk
Characters played by Joan Schofield
Woman Shopper
Characters played by Charles Stevenson
Worker
Characters played by Alfred Wright
Worker
Characters played by Paula Wright
Worker