Fox, America's creepiest TV network, has come up with yet another creepy creep-out: "Intensity," a two-part movie based on a novel by Dean Koontz, an author who likes to frighten people. Unfortunately, "Intensity" is easily as sickening as it is scary.

Aiming to follow in the footsteps of "The Silence of the Lambs," Fox's "Intensity" pits a brave though self-doubting young woman against a murderous male mastermind. The killer, called Edgler Vess, doesn't literally devour his victims (a la Hannibal Lecter in "Lambs") but he does take perverse pleasure in watching them suffer and expire.

The four-hour film, rated TV-14, airs tonight and tomorrow night at 8 on Channel 5. Do you remember when 8 to 9 p.m. was called the family hour and was supposed to be devoted to wholesome entertainment? The only family-hour thing about "Intensity" is that the killer slaughters an entire family during the first hour.

"Intensity" starts, though, with a prologue depicting violence that occurred years earlier. When our heroine, Chyna Shepherd (Molly Parker), was a little girl, she was brutally abused by her drunken, dope-dealing daddy. At 7, the child watches as Pops pumps five bullets into a neighborly couple visiting from next door -- killing them, he says, because he can't abide the middle class.

Throughout the movie we keep returning to tortured scenes from Chyna's traumatic childhood -- her father chasing her with a knife, or the little girl hiding under a bed while her parents have besotted sex upon it. Just to make that particular scene more gross, a giant cockroach crawls up the child's leg as she huddles in horror.

It turns out that her nightmarish childhood was good training for the ordeal she will face as an adult. Invited home by a girlfriend for Thanksgiving, which happens to be the very weekend that Edgler has reserved for his homicidal house call, Chyna finds her friend from school chained to a bed and bleeding profusely.

Eventually, Chyna stows away in the killer's motor home as he drives back to his lair, with a stop along the way to murder two more people at an all-night gas station. Edgler lives in a fenced compound guarded by three German shepherds who were Dobermans in the novel and who'd just as soon sink their choppers into human flesh as into a porterhouse steak.

Chyna has secretly tagged along because Edgler let it be known that he has a 15-year-old girl named Ariel locked in his basement and is waiting for the day she will "ripen" like a "peach" and presumably be deflowered by him, then killed. Scarred by her own background, Chyna is determined to free the girl and spare her the same kind of nightmare.

As adapted by Stephen Tolkin and methodically directed by Yves Simoneau, "Intensity" is certainly not without its shocks and scares. But the whole thing is so stomach-churning and nasty that you don't so much watch it as subject yourself to it. Life is really much too short to spend four hours of it with a preening, prancing monster like Edgler Vess.

John C. McGinley, who plays Edgler, has never had much problem handling creepy roles. But the film has to be padded out to fill four hours of air time, and that means giving McGinley long and tedious speeches about his philosophy of life and his delight in the "intense" feelings he gets when watching somebody drop dead.

Piper Laurie, a wonderful actress, is wasted in the tiny role of a passerby who might have been able to stop Edgler in his tracks if only she weren't an incoherent nincompoop. In addition, some of the decisions made by Chyna also seem far-fetched and lame-brained, merely devices to thicken the plot.

A scene that one reviewer called the most nauseating in the book, Edgler eating a live spider, has mercifully been eliminated. But much that is repellent and gratuitously ghastly remains.

The killer claims to have heightened senses and seems particularly obsessed with his sense of smell, sniffing his victims and savoring the various odors. As you may have deduced, the odor given off by "Intensity" is anything but savory. In a word: pee-yew. CAPTION: Do-gooder Molly Parker meets do-badder John McGinley in Fox's two-parter based on the Dean Koontz novel.