Known to Americans as FIVE MILLION YEARS TO EARTH. Alien bugs in this Quatermass story. Third in the series. The first was THE QUARTERMASS EXPERIMENT (THE CREEPING UNKNOWN). There's a very cosmic background to these ancient invaders that are unearthed below London's subway system and there's still a spark of life waiting to explode upon civilization. Alien pests the toughest to get rid of once you got 'em.