Professor Quatermas (Brian Donlevy) launches a space rocket with three men on board. It unexpectedly crashes back to earth in a field in England with two of the crew missing. The surviving third crewman (Richard Wordsworth) starts to become an alien. Richard Wordsworth gives a good performance as the man becoming an alien. This is an effective early British Sci-Fi film produced by Hammer Films which was a commercial success for them and was based on the BBC TV series.