Quatermass is the director of an important scientific base, where he builds nuclear rockets for the colonization of the Moon. A strange fall of meteorites in a nearby village leads to the discovery of a huge base under a strict military control, officially a factory of artificial food. Quatermass reveals that the factory is actually breeding alien creatures.

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.