The sum of "The Core," a science-fiction film, does not equal its parts, and for a film in which a balanced equation is vital to plot, it makes for a let down.

With A-list actors, an intriguing concept and some good special effects, this film seems like a guaranteed good time. However, weak dialogue, plot holes and some hokey effects take a toll on the film's overall structure.

The film stars Aaron Eckhart as dedicated professor Josh Keyes. He's obviously very intelligent, and we learn right off that he's so dedicated to his work that he has no time for romance. The government calls on him and Dr. Serge Leveque, played by Tcheky Karyo, to give their expertise when odd things start happening around the globe.

For example, 30-some people inexplicably drop dead. Then birds go haywire, flying into buildings and swarming people in big cities. In less than two seconds, Keyes puts two and two together and figures out the Earth's core has stopped moving, which will cause mass destruction and end life on Earth completely. So the government assembles a team of people at the top of their fields to man a wormlike ship to burrow down to the center of the Earth. Once there, the crew will set off nuclear explosions in hopes of restarting the core's rotation.

The premise is somewhat fantastic in itself and to ask an audience to suspend disbelief for more than two hours is too much to ask.

The cast gives a good solid effort to make the plot believable, but they aren't given much to work with in the script. Eckhart infuses Keyes with earnest intelligence and delivers one-liners with the smug nonchalance of a young Harrison Ford. Oscar winner Hilary Swank plays Major Rebecca "Beck" Childs, an astronaut for NASA, chosen to pilot the ship. She does a good job of looking stern and focused, but the film falls apart a bit in the scenes where Childs and Keyes are forced to flirt. There is no chemistry. And perhaps director Jon Amiel realized this early on, because that storyline is dropped halfway through.

The remainder of the crew includes a deliciously egotistic Stanley Tucci playing scientist Conrad Zimsky, Delroy Lindo playing Ed "Braz" Brazzelton, creator of the ship, as a sympathetic mad scientist, and first in command Richard Iverson, played by Bruce Greenwood, who serves as a throw-away character obviously designed to teach Childs a thing or two about leadership.

It is a good crew full of great character actors as well as strong heroes, but the script never allows them to grow emotionally and they become simplistic plot devices that merely keep the action flowing from one special effect to the next.

While some of the effects are realistically shot and well-directed, such as the destruction of San Francisco's Golden Gate Bridge by a freak electrical storm, others remind of science fiction B movies that used awkward pint-sized models to portray monsters or ships in space. The shots of the ship burrowing through the Earth could have been better executed.

It seems every disaster movie has its scenes where familiar monuments or buildings meet a powerful demise. In this case it happens to be Rome's Coliseum and the aforementioned San Francisco bridge.

Fans of science fiction may enjoy the far-fetched plot and technical jargon, but on the whole it seems the film may have had too many parts to juggle effectively. With so many balls in the air, "The Core" loses its central focus, momentum and ultimately, its "core"-relation with the audience.

"The Core"

Rated - PG-13

for sci-fi life-death situations and brief strong language

Starring: Aaron Eckhart, Hilary Swank and Stanley Tucci,

Director: Jon Amiel

Length: 135 minutes

Now playing at: Astoria Gateway Cinemas, Cannes Cinema in Seaside and Neptune Twin Theatres in Long Beach, Wash.

Short take: Director Jon Amiel assembles a great cast and inserts some good special effects in this sci-fi doomsday film that pins the survival of the planet on a crew of brilliant scientists and a couple of skilled pilots. However, a clumsy script and, an at times, B-movie feel make "The Core" hard to sit through.

Rating: Two stars

Rating system:

Four stars: Absolutely the best

Three stars: Good, solid entertainment

Two stars: Wait for the video

One star: Don't waste your time

Movie Trivia: After which recent tragic event did the film's producers recall promotional trailers to remove a scene?

Movie Trivia answer: After the crash of the space shuttle Columbia, trailers for the film were recalled to remove a scene of a space shuttle making an emergency landing. However, the sequence was not removed from the actual film.