X: The Unknown (1956)

After a mysterious explosion leaves a large fissure in the ground, two young boys are confronted by an unknown phenomenon that inflicts severe radiation burns on one of them. There follows a spate of attacks at radiation establishments as the inexplicable life-form plunders radium stores. Dr Royston, an expert in atomic research, is brought in to explain and curtail the activities of this alien creature before it causes disaster.

Genre: Mystery | Sci-Fi | Horror

Country: United Kingdom  

themoviedb.org: https://www.themoviedb.org/movie/26865

IMDb: https://www.imdb.com/title/tt0049967/

Director(s) / Writer(s):

Leslie Norman

Joseph Losey

Jimmy Sangster

Cast:

Dean Jagger

Dr. Adam Royston

Leo McKern

Inspector McGill

William Lucas

Peter Elliott

Edward Chapman

John Elliott

John Harvey

Maj. Cartwright

Anthony Newley

LCpl. 'Spider' Webb

Ian MacNaughton

Pvt. Haggis

Peter Hammond

Lt. Bannerman

Michael Ripper

Sgt. Harry Grimsdyke

Kenneth Cope

Pvt. Lansing

Michael Brooke

Willie Harding

Frazer Hines

Ian Osborn

Neil Wilson

Russell

Jameson Clark

Jack Harding

Jane Aird

Vi Harding

And 7 more...

Trailer: