X the Unknown (1956)

35mm, black and white
mono (RCA Sound System), English

A British science fiction film directed by Leslie Norman who took over from Joseph Losey when the blacklisted American director was forced off the project by the film's star, Dean Jagger, who refused to work with a suspected Communist.

Plot Summary

tests being staged by the British Army at a remote Scottish base disturb a radioactive creature that attacks and kills two soldiers before disappearing. It leaves behind a huge fissure in the earth, then returns and starts attacking with increasing ferocity, absorbing radiation as it goes and growing larger and larger…


* = uncredited

Directed by: Leslie Norman
© MCMLVI [1956] by Sol Lesser Productions, Inc. [US prints only]
Exclusive Films presents [UK prints only] Warner Bros. presents [US prints only] A Hammer Film production
Executive Producer: Michael Carreras
Produced by: Anthony Hinds
Associate Producer: Mickey Delamar *
Production Manager: Jimmy Sangster
Story and Screenplay by: Jimmy Sangster
Assistant Director: Chris Sutton
2nd Assistant Director: Roy Stevens *
3rd Assistant Director: Hugh Harlow *
Continuity: June Randall
Director of Photography: Gerald Gibbs
Camera Operator: Len Harris
2nd Camera Operator: John Reid *
Focus Puller: Harry Oakes *
Clapper Loader: Mike Rutter *
Stills: Tom Edwards *
Editor: James Needs
Assistant Editors: Bill Bouvet *, Henry Richardson *
Music Composed by: James Bernard
Musical Director: John Hollingsworth
Music Recorded at: Anvil Studios *
Sound Mixer: Jock May
Sound Recording: Cliff Sandell *
Sound Camera Operator: Michael Sale *
Boom Operator: Jim Perry *
Sound Maintenance: Charles Bouvet *
Sound Editor: Alfred Cox
Wardrobe: Molly Arbuthnot
Make-up and Special Make-up Effects: Philip Leakey
Special Effects: Bowie-Margutti Ltd., Jack Curtis
Special Effects Assistants: Roy Field *, Ray Caple *, Brian Johnson *
Art Director: Edward Marshall *
Draughtsman: Don Mingaye *
Production Secretary: Margaret Quigley *
Publicity Director: Bill Batchelor *
Produced at: Bray Studios
The Producers wish to acknowledge the co-operation received from the War Office during the production of this film
Casting: Joseph Losey *

Dean Jagger (Dr Adam Royston)
Edward Chapman (John Elliott)
Leo McKern (Inspector McGill)
Anthony Newley (Corporal “Spider” Webb)
Jameson Clark (Jack Harding)
William Lucas (Peter Elliott)
Peter Hammond (Lt Bannerman)
Marianne Brauns (Zena)
Ian MacNaughton (Cpl Haggis)
Michael Ripper (Sgt Harry Grimsdyke)
John Harvey (Major Cartwright)
Edwin Richfield (soldier burned on back)
Jane Aird (Vi Harding)
Norman Macowan (Old Tom)
Neil Hallett (Unwin)
Kenneth Cope (Pvt. Lansing)
Michael Brooke (Willie Harding)
Fraser Hines (Ian Osborn)
Neil Wilson [Russell] *
John Stone [Jerry] *
Edward Judd [second soldier] *

Alternative Titles

X – den ukendte fare – Denmark
X – tuntematon – Finland
X contro il centro atomico – Italy
XX unbekannt – West Germany

Extracts included in
The World of Hammer: Sci-Fi (1994)


Today's Cinema vol.87 no.7586 (15 August 1956) p.9
A reliable cast carries out directorial instructions to the letter and the result is an exciting taste of what could happen in nature really ran riot. Technical effects are first rate. Leslie Norman's direction keeps the story speeding along very ably and the homegoing audience will doubtless consider that no twentieth-century man, woman or child should be without a geiger counter. – from a review by D.R.

Daily Film Renter no.7191 (16 August 1956) p.3
Here is hokum unabashed, racily put together for the delight of the millions with an appetite for the modern vein of fantastic fiction […] A confident line in unscientific ballyhoo comes from Dean Jagger, and the all-male supporting cast is distinctly above-average. Direction makes the most of the unknown quantity, and there are some touches of Army humour. There's nothing “unknown” about this “X” where the popular box-office is concerned. – from a review by S.M.

Kine Weekly no.2557 (16 August 1956) p.23
Gripping science fiction melodrama […] A shrewdly balanced cast, headed by Dean Jagger, the American star, and resourceful direction bring plausibility to the extravagant happenings and keep the interest taut. Realistic atmosphere and detail complete the thrilling oracle. First-rate British shocker. – from a review by Josh Billings

Monthly Film Bulletin vol.23 no.273 (October 1956) p.128
X the Unknown intriguingly suggests a new addition to the science fiction repertoire of Things, but after a series of prolonged climaxes, with its potential victims staring directly into the camera and shaking with fright, the “Unknown” finally emerges as a type of rolling rubber mattress, disappointingly unhorrific in content and appearance. – from an unaccredited review



  • Daily Film Renter no.7191 (16 August 1956) p.3 – review (by S.M.)
  • Fangoria no.184 (July 1999) p.35 – illustrated review
  • Film & TV Technician vol.23 no.145 (January 1957)(UK) – credits (Guide to British Film Makers)
  • The House That Hammer Built no.1 (February 1997) pp.35-40 – illustrated credits, synopsis, production notes (by Wayne Kinsey)
  • Kine Weekly no.2557 (16 August 1956) p.23 – review (by Josh Billings)
  • Monthly Film Bulletin vol.23 no.273 (October 1956) p.128 – review
  • Supernatural no.1 (January 1969) p.28 – note (Round the cinema's zoo of horrors with Supernaturalist)
  • Today's Cinema vol.87 no.7586 (15 August 1956) p.9 – review (by D.R.)


  • The A-Z of Science Fiction and Fantasy Films by Howard Maxford p.299 – credits, review
  • The Aurum Film Encyclopedia: Science Fiction by Phil Hardy (ed.) pp.164-165 – credits, review
  • British Sound Films: The Studio Years 1928-1959 by David Quinlan pp.402-403 – credits, synopsis
  • Elliot's Guide to Films on Video by John Elliot p.890 – credits, review, UK video data
  • English Gothic: A Century of Horror Cinema by Jonathan Rigby pp.50-52, 51, 91, 157, 199, 296, 349 – illustrated notes, review
  • Euro Gothic: Classics of Continental Horror Cinema by Jonathan Rigby p.66
  • Hammer Complete: The Films, the Personnel, the Company by Howard Maxford pp.886-887 – illustrated credits, synopsis, review
  • The Hammer Story by Marcus Hearn and Alan Barnes pp.18-19 – illustrated credits, synopsis, review
  • Heroes, and Values: Science Fiction Films of the 1970s p.61
  • A History of Horrors: The Rise and Fall of the House of Hammer (Revised Edition) by Denis Meikle pp.28-29, 30, 31, 25, 27, 40, 42, 49, 231-232 – notes, review
  • Hoffman's Guide to Science Fiction, Horror and Fantasy Movies 1991-1992 p.401 – credits, review
  • Horror and Science Fiction Films III by Donald C. Willis pp.309-310 – credits
  • Horrorshows: The A-Z of Horror in Film, TV, Radio and Theatre by Gene Wright p.125 – credits, review
  • It Came from 1957: A Critical Guide to the Year's Science Fiction, Fantasy and Horror Films by Rob Craig pp.141-143
  • Nuclear Movies: A Filmography by Mick Broderick p.51
  • by Walt Lee p.552 – credits
  • Uneasy Dreams: The Golden Age of British Horror Films, 1956-1976 by Gary A. Smith p.242