X: The Unknown
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.
Ratings
Based on audience scoresWhere to stream X: The Unknown
Streaming now in the United States on Mometu.
Trailers and promos
4K Restoration | Official Trailer
Original Theatrical Trailer
The Scene That Made Audiences Afraid of the Ground Beneath Them
This Film Was Melting Faces Before Indiana Jones
The Moment Something Terrifying Awoke Beneath The Surface
Joe Dante on X - THE UNKNOWN
Limelight
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Frequently asked questions about X: The Unknown
Where can I watch X: The Unknown in the United States?
X: The Unknown is available to stream on Mometu in the United States. Streaming availability is provided by JustWatch and can change over time.
Can I watch X: The Unknown for free?
X: The Unknown streams free with ads in the United States on Mometu. A subscription is not required, though the service may ask you to register.
What are the ratings for X: The Unknown?
X: The Unknown scores 6.1 on The Movie Database, 6.1 on IMDb, and 45% on Rotten Tomatoes.
Who stars in X: The Unknown?
X: The Unknown stars Dean Jagger, Leo McKern, William Lucas, Edward Chapman, and John Harvey. Leslie Norman is the director.
How long is X: The Unknown?
X: The Unknown runs 1h 21m (81 minutes).
When did X: The Unknown come out?
X: The Unknown was released on September 21, 1956.
Which studio made X: The Unknown?
X: The Unknown was produced by Hammer Film Productions in the United Kingdom.
Ratings and streaming availability are aggregated from third-party sources; metadata from The Movie Database (TMDB), streaming data from JustWatch. This product uses the TMDB API but is not endorsed or certified by TMDB. Streaming availability checked September 2026.