English
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 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 titular "life force" out of a guard. She then escapes the research facility and begins draining 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 of a living being, rather than blood.
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...Italiano
Tre umanoidi uguali ad esseri umani scendono sulla Terra ed iniziano a spargere terrore, assorbendo l'energia vitale delle loro vittime ed iniziando un massacro a cui lo scienziato Carlsen è incaricato dal governo di mettere fine. Ma il suo compito sarà ostacolato da una relazione amorosa con una bella vampira/aliena.
