 Dr. 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. The shrewdness of Quatermass reveals that the factory is the place chosen by the aliens to conquer the Earth: they come in the form of an alive gas hidden in the meteors and to live in our atmosphere they use the human body taking the control of the brain. The courage of Quatermass and the launch of of his nuclear rocket against the asteroid of the aliens save the Earth.