Just when you thought Hollywood had hit rock bottom, along comes "The Core." This sloppily made, poky, extra cheesy adventure is virtually a remake of "Armageddon." Only this time the threat is not an asteroid but a disruption in the Earth's magnetic field. And this time the intrepid types must go underground to explode their nukes if they are to save the world.

Once again the onus is on the military, which has secretly developed and detonated an earthquake bomb (apparently they intend to shake our enemies to death). As a result, the planet's inner core -- which normally whirls like a blender -- is about to stop spinning. This is a bad business indeed, so a hastily assembled team of "terranauts" must travel to the Earth's center to give the rotor a jump-start. And it is one boring trip, too.

Early in this spelunk-headed science fiction, 17 Bostonians drop dead for no apparent reason, while those around them remain perfectly healthy. Fearing that the deaths are related to their machinations, military leaders consult with scientific superstars and crew members Josh Keyes (listless Aaron Eckhart), Sergei Leveque (innocuous Tcheky Karyo) and Conrad Zimsky (campy Stanley Tucci). The doctors quickly ascertain that all the victims wore pacemakers, and their suspicions are definitely aroused.

Josh digs deeper and discovers other strange incidents: Pigeons go all Hitchcock in Trafalgar Square, the Colosseum collapses in Rome and water flows in the ordinarily arid L.A. River. All the evidence indicates that the planet's magnetic field, which shields the planet from solar radiation, is rapidly deteriorating.

According to his calculations, the world will be charcoal in about three months. Luckily, Dr. Ed "Braz" Brazzelton (dotty Delroy Lindo) has spent the last 20 years creating an earthwormlike vessel that will bore through the planet's crust, surf through the fluid mantle and breach the molten inner core.

Top brass recruits Maj. Rebecca "Beck" Childs (Oscar-cursed Hilary Swank), an astronaut, to pilot the vessel. After all, steering a shuttle through a space vacuum is identical to maneuvering a giant metal worm through solid rock, lava-lamp landscapes and sundry phlegmy effects. Beck's other duties include romancing the hero, who's a scruffy, exposition-spouting snore. Even though the temperature reaches 7,000 degrees Celsius, the couple don't sizzle. They don't even work up a sweat.

If only the filmmakers had recognized and relished the material's camp potential, this might have been another "Fantastic Voyage." Maybe director Jon Amiel forgot how to put his tongue in his cheek. Maybe he never knew how.

The Core (133 minutes, at area theaters) is rated PG-13 for disaster sequences and profanity.

Aaron Eckhart and Hilary Swank, stuck in a humorless vehicle.