Prometheus: Alien origins:The skeleton beneath the exoskeleton | Scanners

When one of the crew is infected, the commander of the ship (Ripley in "Alien," Vickers in "Prometheus") tries to prevent the contaminated man from re-boarding for fear of breaking quarantine. The android overrules her and lets them in.

The xenomorph implanted in the body of one of the crew gets loose on the ship.

While there is no "facehugger" in "Prometheus," the alien larvae look like vaginal-headed cobras and can dissolve/penetrate helmets, and they have highly acidic blood.

Eventually, like Ripley (and Kane), Shaw strips to her underwear, emphasizing her vulnerability in this biomechanical setting.

The android is decapitated, but continues to speak.

In an attempt to kill the xenomorph and prevent it from getting back to earth, the ship is destroyed and Shaw/Ripley escapes in a pod. Only it turns out the xenomorph is aboard.

The movie ends with the voiceover log (not unlike the ending of a "Star Trek" episode) of the surviving crew member, who heads off into space.

On the one hand, this is precisely what a "sequel/prequel" is designed to do: to return you to a world you want to revisit. (See "Back to the Future 2," a movie that outdoes the original, in my estimation, by actually taking you inside the first movie and showing it to you from a slightly different point of view -- like a variation on "Rosencrantz & Guildenstern are Dead." Genius). How well it works for you will depend on whether you feel the film is attacking its story with conviction or if it's just ticking off a list of scenes and images from its superior predecessor.

The other "ghost movie" that haunts "Prometheus" (quite consciously on the part of the filmmakers) is, as I said before, "2001: A Space Odyssey."

Long before the birth of humanity, a sentinel is placed on Earth (and, apparently, the moon) by an advanced alien intelligence. It appears to have accelerated the evolution of mankind. (In "Prometheus," it's the actual introduction of "engineer" DNA; in "2001" it's more of a catalyst, giving primates the inspiration for using tools/weapons.)

Eons later, the sentinel is unearthed (on Earth in "Prometheus"; on the moon in "2001"). A team of explorers, some in cryonic hibernation, is sent into deep space to investigate.