Workers building an extension to the London Underground at Hobbs End dig up a skull that identifies as a five-million-year-old apeman. Part of a metallic object is uncovered nearby. Believing it to be an unexploded bomb from the London blitz, they call in an army bomb disposal team. Professor Bernard Quatermass learns that his plans for colonizing the Moon are to be taken over by the military, who want to establish missile bases in space. When the bomb disposal team call for assistance, Quatermass accompanies them to the site. They realize that the object itself must also be five million years old. Noting its imperviousness to heat, Quatermass suspects it is of alien origin.