X: The Unknown
“It rises from 2000 miles below the earth to melt everything in its path!”
Army radiation experiments awaken a subterranean monster from a fissure that feeds on energy and proceeds to terrorise a remote Scottish village. An American research scientist at a nearby nuclear plant joins with a British investigator to discover why the victims were radioactively burned and why, shortly thereafter, a series of radiation-related incidents are occurring in an ever-growing straight line away from the fissure.
Where to watch X: The Unknown in United States
MometuClick a service to open X: The Unknown there. Availability last verified on June 20, 2026.
Where is X: The Unknown streaming around the world?
| Country | Streaming on | Rent / Buy |
|---|---|---|
| United States | Mometu | — |
| United Kingdom | Amazon Prime Video, Amazon Prime Video with Ads | Amazon Video, Google Play Movies, YouTube |
| France | Molotov TV | — |
| Spain | Filmin | — |
About X: The Unknown
X: The Unknown is a 1956 English-language horror, science fiction and mystery film directed by Leslie Norman. The cast is led by Dean Jagger, Leo McKern, William Lucas. It has a runtime of 1h 21m. Viewers rate it 6.1/10 across 100 ratings. In United States, it is currently streaming on Mometu.
X: The Unknown was produced by Hammer Film Productions and made in United Kingdom. It was released on September 21, 1956, and carries a PG certification.
- Director
- Leslie Norman
- Writers
- Jimmy Sangster
- Release date
- September 21, 1956
- Original language
- English
- Age rating
- PG
- Status
- Released
- Country
- United Kingdom
- Production
- Hammer Film Productions
X: The Unknown cast & crew
X: The Unknown was directed by Leslie Norman and written by Jimmy Sangster.
The cast features Dean Jagger as Dr. Adam Royston, Leo McKern as Inspector McGill, William Lucas as Peter Elliott, Edward Chapman as John Elliott, John Harvey as Maj. Cartwright, and Michael Ripper as Sgt. Harry Grimsdyke.
Behind the camera, the score was composed by James Bernard, cinematography is by Gerald Gibbs, and it was produced by Anthony Hinds and Michael Carreras.
Is X: The Unknown worth watching?
X: The Unknown holds an audience score of 6.1/10 from 74 ratings, a solidly received horror films.
At 1h 21m, it's an easy, time-light watch.
If you enjoy horror, science fiction, and mystery, X: The Unknown is worth a place on your watchlist.
How and where to watch X: The Unknown
In United States, you can stream X: The Unknown on Mometu. Click any service above to open it directly.
Streaming rights change country by country and month by month, so the options above reflect United States today — switch your country at the top of the where-to-watch section to see availability elsewhere.
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Cast of X: The Unknown
Dean Jagger
Dr. Adam Royston
Leo McKern
Inspector McGill
William Lucas
Peter Elliott
Edward Chapman
John Elliott
John Harvey
Maj. Cartwright
Michael Ripper
Sgt. Harry Grimsdyke
Anthony Newley
LCpl. 'Spider' Webb
Ian MacNaughton
Pvt. Haggis
Peter Hammond
Lt. Bannerman
Kenneth Cope
Pvt. Lansing
Michael Brooke
Willie Harding
Frazer Hines
Ian Osborn
X: The Unknown — FAQs
▸Where can I watch X: The Unknown in United States?
X: The Unknown is streaming on Mometu in United States.
▸Is X: The Unknown on Mometu?
Yes — X: The Unknown is currently available on Mometu in United States.
▸What language is X: The Unknown in?
X: The Unknown is originally in English. Subtitle and dub options vary by streaming service.
▸How long is X: The Unknown?
X: The Unknown runs 1 hours 21 minutes (81 minutes).
▸What is X: The Unknown rated?
X: The Unknown is rated PG. It holds a 6.1/10 audience score from 74 ratings.
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