English science fiction films of the 1950s were mostly low budget efforts, often adaptations of teleplays. The box office success of Hammer Films' The Quatermass Xperiment (1955) inspired more thrillers in which scientists combat aliens and monsters. In 1958 Eros Films adapted René Ray's TV serial The Strange World of Planet X for the screen. For U.S. release it was re-titled The Cosmic Monster but was advertised as simply Cosmic Monsters. The formulaic tale sees experiments at a rural laboratory causing a number of unintended consequences. The lab's 'magnetic fields' open a broad hole in the ionosphere, admitting cosmic rays that turn a hobo into a mad killer and cause insects and centipedes to grow into oversized monsters. Lab assistant Gil Graham (American actor Forrest Tucker) looks out for sexy colleague Michele (Gaby André), while schoolteacher Helen (Patricia Sinclair) is trapped in a classroom besieged by a horde of half-seen insect horrors, which are shown battling the army via macro-photography, mattes and rear-projection. The narrative confusion gives the movie a definite surreal effect, especially in a grisly scene that shows a huge insect gnawing on a dead soldier's face. To top it all, an unemotional alien (Martin Benson) shows up to complain that the experiment has caused one of his flying saucers to crash. The polite discussion regarding the fate of the Earth takes place in a country café, which in its own way is also rather surreal.

By Glenn Erickson