Lifeforce is a 1985 science fiction film directed by Tobe Hooper, based on the 1976 novel, The Space Vampires, by Colin Wilson. The screenplay was written by Dan O'Bannon and Don Jakoby. Featuring Steve Railsback, Mathilda May, Patrick Stewart and Christopher Jagger (Mick Jagger's brother) in acting roles, the film portrays the fictional events that unfold after three mysterious humanoids, discovered in a space shuttle, are taken to Earth.
While investigating Halley's Comet, the crew of the space shuttle Churchill finds a 150-mile long spaceship hidden in the corona of the comet. Upon entering the alien craft, the crew finds hundreds of dead, shrivelled bat-like creatures and three naked humanoid bodies (two male and one female) in suspended animation within glass coffin-like containers. The crew recovers the three aliens and begins the return trip to Earth.
During the return journey, mission control loses contact with the shuttle as it nears Earth and a rescue mission is launched to investigate. The rescuers discover that the Churchill has been severely damaged by fire, with its internal components destroyed, and the three containers bearing the aliens are all that remain intact. The aliens are taken to the European Space Research Centre in London where they are watched over by Dr. Leonard Bukovski (Michael Gothard) and Dr. Hans Fallada (Frank Finlay). Prior to an autopsy, the female alien (Mathilda May) awakens and sucks the titular "life force" out of a guard. The female then escapes the research facility and proceeds to drain various other humans of their life force, also revealing an ability to shape-shift. It transpires that the aliens are from a race of space vampires that consume the life force of living beings, rather than their blood.