Sam Bell (Sam Rockwell) wakes up every morning, quite fittingly, to the sounds of Chesney Hawkes' "The One and Only." Approaching the final two weeks of his three-year contract on the moon, where he is assisting in the mining of energy resource Helium-3, he has begun to go a little stir-crazy. Save for robotic assist GERTY (voiced by Kevin Spacey), Sam has been living in total isolation with no one to talk to but himself, his only connection to the outside world being recorded video transmits from the company heads of project funder Lunar Industries and his beloved wife, Tess (Dominique McElligott). He also has begun to experience strange hallucinations—e.g., a dark-haired woman sitting in a chair, odd disconnected frames pieced into Tess' taped messages—but chalks them up to being his lonely mind playing tricks on him. When Sam awakes back at mining base Sarang after getting into a rover crash, he first regains his strength and then goes to investigate the wrecked vehicle. What he finds inside is a copy of himself, banged up but still alive. Is the Sam who woke up back at the base the same one who got in the accident? How can there now be two of them? And if they aren't the same person, why do they share identical memories?

The promising directorial debut of Duncan Jones (for those not in the know, David Bowie's son), "Moon" is esoteric and a little frightening, a serious-minded sci-fi rumination for viewers who strive for more out of their genre pieces than pyrotechnics and jive-talking scraps of metal. Reminiscent of 2002's underappreciated "Solaris" and 2007's "Sunshine," the film creates a thick pall of dread and despair without the conventional means of tossing evil aliens or supernatural beings into the plot. Instead, the dangers in "Moon" are understated but apparent, slightly futuristic in design but also fully plausible. Jones and first-time screenwriter Nathan Parker ask tough questions of the audience, urging them to place themselves in Sam's shoes. What would it really be like to live in a deserted mining station by yourself for three solid years? How would that affect one's mind, personality, and actions? With the appearance of a second Sam, the stakes are raised, and as the true nature of what is going on is revealed, the questions become ethics-based. Suspicious of each other while fearing that the other one might make their own life invalid, the two Sams have no choice but to stare the truth of who they are and where they come from—not to mention the cruelties of time and aging—squarely between the eyes.

The pacing of "Moon" is deliberate, almost dreamlike, pulling the viewer into the mysteries at its core while taking its sweet, old time in setting up its remote, eerily quiet, antiseptic-white surroundings. This is appropriate, however, since Sam Bell's day-to-day work is repetitive and routine, and the setting is a character all its own. Emotionally, the picture is perhaps a little too chilly. In the similar "Solaris," the characters were warmer, the tragic relationship between George Clooney and Natascha McElhone heartbreaking as it developed and clarified itself. With "Moon," there is less of a connection to Sam because our glimpses into his past and personality prior to leaving for the space mission are so brief. Thus, the viewer is happy to grapple with the film's headier themes, but does not necessarily care as much on a human level about the fates of both Sams.

Sam Rockwell (2008's "Choke") is without fault, immaculate in his portrayal of Sam Bell and Sam Bell. As if it weren't difficult enough having to star in a movie basically by yourself, Rockwell has to play two copies of the same man while successfully differentiating them. The optical trickery and special effects involved in this process are seamless, but it is Rockwell who really sells the idea. Never does the viewer really think about how Rockwell is performing both parts; it is almost as if a long-lost twin was somehow cast alongside him. As the voice of GERTY, a pretty shameless knock-off of HAL from "2001: A Space Odyssey," Kevin Spacey (2008's "21") is indelible, perfectly cast. That GERTY remains an empathetic, albeit mechanical, friend to Sam throughout is a welcome twist on the typical formula of the robot turning against the humans.

A solid piece of work with a brain to counteract its not consistently fresh ideas, "Moon" is most notable for its introduction to clearly talented filmmaker Duncan Jones. For what one presumes was a low-budget production, visual effects are beautifully mounted, believably making it seem like it was filmed on the actual dark side of the moon. In addition, the music score by Clint Mansell (2008's "The Wrestler") is composed with a haunting, yet catchy, simplicity, and the picture as a whole leaves the viewer pondering its provocations long after the end. "Moon" is technically and intellectually impressive, but nonetheless leaves the viewer's heart curiously unmoved. It is this that ultimately downgrades what could have been a great movie to a merely good one.