"Lifeforce" is a movie about Halley's Comet, and if we're lucky, we won't see another like it for 75 years. It's an expensive cheap exploitation movie -- millions for special effects but not a penny for screen writing -- that will bore even the most hard-core of sci-fi devotees.

When the spaceship Churchill goes to investigate the comet, it discovers two women and a man in suspended animation; one woman (Mathilda May) is a seductress, but when she kisses a man, electrical sparks flit between them and his whole body shrivels and collapses like a shrunken head.

Hello, Dr. Ruth? I have this problem . . .

Only astronaut Carlsen (Steve Railsback) survives; the woman, you see, is in love with him. The ship returns, the woman escapes to kiss and kiss again, draining the "lifeforce" from each of her partners, who then must seduce others to recover that lifeforce. All London is turned into a race of libidinous vampires. (This is London?) After an hour of this, you're starting to feel the way they look.

"Lifeforce" is the kind of movie where people are always looking off into the distance and saying gravely, "We have to expect the worst," or getting inflamed and saying, "You don't know what we're dealing with here!" Mostly, though, they say "AAAAAARGH!" Between the shouting and the noise and the overproduced music (by Henry Mancini, of all people), you can't hear half the dialogue anyway.

The special effects aren't all that special -- it's just stuff we've seen before (in director Tobe Hooper's own "Poltergeist," for example). Worse, they're not worked into the story, because there is no story. The screenplay, by Dan O'Bannon and Don Jakoby, is just one long passage of exposition: someone blows up or dries up or whatever, you wonder why that's happening, and then someone explains it. This they call suspense.

Some people can make money out of anything, and shlockmeister producers Menahem Golan and Yoram Globus are two of them. What "Lifeforce" is, of course, is a thinly veiled AIDS parable. The vampire woman tells Carlsen, "I am the feminine in your mind"; the draining of the lifeforce makes everyone sexually insatiable; the coupling creates a plague. The answer, in the movie, is to drive a spike through the creature's solar plexus. Thanks, fellas.