Based on a BBC television mini-series, Hammer decided to produce a feature film of THE QUATERMASS XPERIMENT starring BRIAN DONLEVY as Professor Quatermass. The title of the film is also known also as "The Creeping Unknown". The plot evolves around an astronaut monstrously enveloped by an alien fungus and must be destroyed by the scientists with the help of police and firemen. It's all done in straightforward sci-fi manner, but all of it looks low-budget as though not much thought was given to developing the story's full potential as a thriller. BRIAN DONLEVY delivers what can only be called a robotic performance, as though sedated under either medication or alcohol to the point where he remains as expressionless as a mechanical doll. This aspect of his portrayal makes him almost as creepy as the astronaut invaded by the alien fungus. Hard to see why this was such a huge hit when it opened back in 1955, since it merely borrows heavily from films like INVASION OF THE BODY SNATCHERS which was far above it in concept and originality and it fails to reach the same amount of horror or thrills.

source: The Creeping Unknown

Trailer—The Quatermass Xperiment

The Quatermass Xperiment