Lifeforce is a 1985 science fiction film directed by Tobe Hooper from a screenplay by Dan O'Bannon and Don Jakoby, from the novel The Space Vampires, published in 1976, by Colin Wilson. The film performed badly on its original release.
While investigating Halley's Comet, the crew of the space shuttle Churchill finds a 150 mile long spaceship hidden in the coma of the comet. Upon entering the alien spacecraft, the crew finds hundreds of dead and 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 sent to find out what happened on board. The rescuers find the Churchill completely gutted by fire, except for the three suspended animation cases bearing the aliens. All three are taken to 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 taking place the naked female 'vampire' (Mathilda May) awakens and sucks the lifeforce out of a guard. She then escapes the research facility and begins sucking various humans of their life force and moving through various host bodies. It transpires the aliens are a race of space vampires that consume the life force from living beings that is subsequently uploaded to their ship. Meanwhile, in Texas, an escape pod from the shuttle Churchill is found with Col. Tom Carlsen (Steve Railsback) still alive. He is flown to London and tells how the crew were drained of their life force. To save Earth from this fate, Carlsen set fire to the shuttle and escaped in the pod. During hypnosis it is clear Carlsen has a psychic link to the female alien. Carlsen and Col. Colin Caine (Peter Firth), a member of the SAS, trace the alien to the body of a nurse at a hospital for the mentally disturbed in Yorkshire. They believe they have managed to trap the alien girl within the heavily sedated body of the hospital's manager, Dr Armstrong (Patrick Stewart). However, the entire episode was a trick to lure them away from London. As Carlsen and Caine are transporting Dr Armstrong in a helicopter back to London, the alien girl breaks free from a sedated Dr Armstrong and disappears. When they arrive back in London it is clear that a plague has taken full control - even the prime minister has been infected and martial law has been enacted to prevent the spread of the plague out of London. The two male vampires have also escaped from confinement and begun to transform most of London's population into zombies. Once transformed, the victims cycle into living-dead every two hours and seek out the living, absorbing the life force from their victims. These people themselves become vampires and the transformation process repeats. This energy is then collected by the male vampires who direct it to the female vampire who transfers it to the waiting spaceship in Earth's orbit. Fallada manages to impale one of the male vampires with a sword made of lead. He surmises that the legends of vampires may well be drawn from a previous visit by this space vampire race. Carlsen then admits to Caine that whilst on the shuttle he felt compelled to open the female vampire's container and to have shared his life force with hers. Carlsen realises his psychic connection is being used to lure him back to the alien so she can regain the life force she shared with him. She is located lying upon a church's altar transferring the energy to her spaceship. Caine follows Carlsen and dispatches the second male vampire (with the lead sword, obtained from Fallada, who Caine had to kill due to becoming infected as with the others at the research centre) before locating Carlsen who sacrifices himself by impaling himself and the female alien in the process. Wounded but not fatally, the female vampire returns to her ship, releasing a burst of energy that blasts the top off the church building in the process and taking Carlsen with her. The two ascend up the column of light to the vessel, which then departs towards the comet it came from.