The Quatermass Xperiment

The Quatermass Xperiment is a 1955 British science-fiction / horror film, based on the 1953 BBC Television serial The Quatermass Experiment by Nigel Kneale.

This feature film version was adapted by the director, Val Guest, working with screenwriter Richard Landau. It was produced by the Hammer Films company, who changed the title to The Quatermass Xperiment with the strange spelling in order to play on the film's X-certificate status, claiming that it was the first British-made movie to have received such a classification. In America, the film was released under the title The Creeping Unknown, and some prints screened on British television have used the conventional spelling.

The film starred American actor Brian Donlevy as Professor Bernard Quatermass, the lead role having gone to him in an attempt to appeal to the North American audience. Other actors to appear included future Dixon of Dock Green star Jack Warner and future Dame, Thora Hird. Jane Asher also made an uncredited appearance as a small child, her first screen role.

The film was quite popular at the time, successful enough for Hammer to produce adaptations of the following two Quatermass serials, releasing them to the cinema as Quatermass 2 (1957) and Quatermass and the Pit (1967). It is also of special interest today as a complete copy of the original BBC television version of the story no longer exists, although Quatermass creator Nigel Kneale did not like the film version and was particularly displeased with Donlevy's performance in the lead role.

The plot of the film appears to have been a major influence on the 1999 Johnny Depp movie