The British Experimental Rocket Group launches a manned space ship and Professor Bernard Quatermass (Jason Flemyng) joins his colleagues John Paterson (Mark Gatiss) and Judith Carroon (Indira Varma) in tracking the rocket's journey. When all contact is lost Judith has extra cause for concern - her husband, Victor (Andy Tiernan), is one of the three astronauts on board.

The rocket crash lands but only Victor emerges, clearly afflicted with a debilitating illness. Dr Gordon Briscoe (David Tennant) joins Quatermass in trying to diagnose Carroon's strange contamination.

Carroon escapes and Ministry of Defence investigator Lomax (Adrian Dunbar) leads a desperate hunt across London. As Carroon's horrifying mutation accelerates, Quatermass realises that his experiment has placed the whole of mankind in jeopardy...