Barry Levinson's adaptation of Michael Crichton's novel Sphere has more in common with the story's focal otherworldly orb than just its title. The sphere is luminous and hauntingly beautiful on the surface, with its interior kept alluringly, frustratingly unclear--much like the superficially diverting but ultimately disappointing film itself.

A four-man team comprised of psychologist Norman Goodman (Dustin Hoffman), biochemist Beth Halperin (Sharon Stone), mathematician Harry Adams (Samuel L. Jackson), and astrophysicist Ted Fielding (Liev Schreiber) is recruited by the government to investigate the wreckage of a crashed spacecraft at the bottom of the ocean. Inside the spacecraft, the team discover a giant, glowing, golden sphere of unknown origin. But soon after this discovery, strange, life-threatening occurrences befall the team in their undersea station, from the appearance of giant sea creatures to online contact with a possibly extraterrestrial lifeform.

This is a solid jumping-off point for a intelligent, suspenseful sci-fi thriller, and while there are some very effective moments, the murky script by Stephen Hauser and Paul Attanasio keeps Sphere from taking on a defined shape. Sphere does eventually offer answers to its mysteries, but the information is often too unclearly stated and clumsily delivered. Tune out for one second, and one crucial, isolated line of dialogue that reveals one of the film's key mysteries is lost, the information never to be repeated again. One more irksome miscalculation was the division of the action with chapter title inserts, such as "The Surface," "The Deep," "The Spacecraft," and so on. I suppose the purpose was to underscore certain important parts of each section, but the chapter divisions hamper the building of any suspense, which is hard to sustain once an obtrusive title card appears.

But Levinson is able to overcome that start-and-stop rhythm and gradually build tension, resulting in some memorable shock scenes. The film's final act, where suspicion is hovers over all of the central characters, is particularly tense and well-acted by the three above-the-title stars. It is quite refreshing to see a science fiction film that relies more on wits and psychological terror to drive its climax than visual effects (though the effects are quite impressively handled).

Ultimately, Sphere ends up running out of gas before the film reaches the end of its two-hour-plus running time. After the strong climax, the film drags on for about another 15 minutes, blunting the impact of all that went on before with a finale that, while well done technically, is on the cornball side. Much like the mysterious object that lends the film its title, Sphere offers its share of surface delights, but what exactly lies underneath--if anything at all--is left up to question.