Lifeforce is a 1985 British science fiction horror film directed by Tobe Hooper, adapted by Dan O'Bannon and Don Jakoby, and starring Steve Railsback, Peter Firth, Frank Finlay, and Mathilda May.

[10][11][12] The crew of the joint British and American Space Shuttle Churchill, under the command of Colonel Tom Carlsen, finds a 150-mile-long (240 km) spaceship hidden in the coma of Halley's Comet.

Inside, the crew discovers hundreds of desiccated bat-like creatures and three naked humanoid bodies (two male and one female) in suspended animation within glass containers.

The two male vampires awaken and violently attempt escape, but are apparently destroyed by grenades thrown by another guard.

The two male vampires have survived by shapeshifting into the soldiers who killed their previous bodies, and now are infecting London's population.

In an interview, director Tobe Hooper discussed how Cannon Films gave him $25 million, free rein, and Colin Wilson's book The Space Vampires.

"[15][16][17] The screenplay was written by Dan O'Bannon and Don Jakoby (both would also collaborate with Tobe Hooper in Invaders from Mars).

"[22] In February 1984, Billy Idol said he had been offered a lead role as a vampire by Hooper, who had directed the video of "Dancing with Myself", but turned it down due to touring commitments.

[23][24] In April 1984, John Gielgud said "I was recently offered an enormous sum to play in a film called Space Vampires, and I nearly fell for it because it would have been nice to have had the money.

One effect near the end of the film involving the column of energy rising from the female alien through the top of St. Paul's Cathedral to the spacecraft was engineered by art director Tony Reading.

A column of retroreflective material was placed against black velvet and a crew member blew cigar smoke into its bottom.

[28] For the American domestic version, Michael Kamen and James Guthrie were asked to write occasional music cues that were placed in at the last minute.

[18] As a result, the title was changed to Lifeforce, referring to the spiritual energy the space vampires drain from their victims, and it was edited for its US theatrical release by TriStar Pictures into a 101-minute domestic cut that was partially re-scored by Michael Kamen, with a majority of Henry Mancini's original music remaining.

This is 12 minutes longer than the final version which had several scenes cut, most of them taking place on the Space Shuttle Churchill.

According to Nicholas Ball, who played the main British astronaut, Derebridge, it was felt that there was too much material in outer space and so the majority of the Churchill scenes were deleted.

Also, most of Nicholas Ball's performance ended up on the cutting room floor according to an interview he gave on the UK talk show Wogan in 1985.

The Churchill commanding officer Rawlins, played by Geoffrey Frederick, was British, but in post-production it was decided that Patrick Jordan would dub his voice.

[31] Janet Maslin, of The New York Times, wrote, "[I]ts style is shrill and fragmented enough to turn Lifeforce into hysterical vampire porn.

"[33] Michael Wilmington, in the Los Angeles Times, wrote that the film was "such a peculiar movie [that] it's difficult to get a handle on it".

"[38] Andrew Migliore and John Strysik, in their Lurker in the Lobby, explained that Colin Wilson wrote The Space Vampires as a consequence of H.P.

Lovecraft's publisher August Derleth challenging Wilson (who was critical of Lovecraft's writing) to write a Lovecraftian novel himself (a challenge that resulted in three such novels, The Mind Parasites, The Space Vampires, and The Philosopher's Stone), and they continued, "Lifeforce is big, splashy, and...the scenes of an apocalyptic London are not to be missed.

The consensus reads, "Brazenly strange and uneven in its execution, Lifeforce is an otherworldly sci-fi excursion punctuated with off-kilter horror flourishes.