Although the impeding water robbed the blow of most of its force, I gasped, swallowed, choked on the taste of chlorine flavored with tanning oil. Losing my grip on Harlo, I tumbled in slow-mo through undulant curtains of green light, blue shadow, and broke the surface into spangles of sunshine.

I was in the middle of the pool, and Harlo was at the edge. He grabbed the coping and jacked himself onto the concrete deck.

Coughing, venting atomized water from both nostrils, I splashed noisily after him. As a swimmer, I have less potential for Olympic competition than for drowning.

On a particularly dispiriting night when I was sixteen, I found myself chained to a pair of dead men and dumped off a boat in Malo Suerte Lake. Ever since then, I've had an aversion to aquatic sports.

That man-made lake lies beyond the city limits of Pico Mundo. Malo Suerte means "bad luck."

Constructed during the Great Depression as a project of the Works Progress Administration, the lake originally had been named after an obscure politician. Although they have a thousand stories about its treacherous waters, nobody around these parts can quite pin down when or why the place was officially renamed Malo Suerte.

All records relating to the lake burned in the courthouse fire of 1954, when a man named Mel Gibson protested the seizure of his property for nonpayment of taxes. Mr. Gibson's protest took the form of self-immolation.

He wasn't related to the Australian actor with the same name who would decades later become a movie star. Indeed, by all reports, he was neither talented nor physically attractive.

Now, because I hadn't been burdened on this occasion by a pair of men too dead to swim for themselves, I reached the edge of the pool in a few swift strokes. I levered myself out of the water.

Having arrived at the sliding door, Harlo Landerson found it locked.

The pajamaed woman had disappeared.

As I scrambled to my feet and started to move, Harlo backed away from the door far enough to get momentum. Then he ran at it, leading with his left shoulder, his head tucked down.

I winced in expectation of gouting blood, severed limbs, a head guillotined by a blade of glass.

Of course the safety pane shattered into cascades of tiny, gummy pieces. Harlo crashed into the house with all his limbs intact and his head still attached to his neck.

Glass crunched and clinked under my shoes when I entered in his wake. I smelled something burning.

We were in a family room. All the furniture was oriented toward a big-screen TV as large as a pair of refrigerators.

The gigantic head of the female host of the Today show was terrifying in such magnified detail. In these dimensions, her perky smile had the warmth of a barracuda's grin. Her twinkly eyes, here the size of lemons, seemed to glitter maniacally.

In this open floor plan, the family room flowed into the kitchen with only a breakfast bar intervening.

The woman had chosen to make a stand in the kitchen. She gripped a telephone in one hand and a butcher knife in the other.

Harlo stood at the threshold between rooms, trying to decide if a twentysomething housewife in too-cute, sailor-suit pajamas would really have the nerve to gut him alive.

She brandished the knife as she shouted into the phone. "He's inside, he's right here!"

Past her, on a far counter, smoke poured from a toaster. Some kind of pop-up pastry had failed to pop. It smelled like strawberries and smoldering rubber. The lady was having a bad morning.

Harlo threw a bar stool at me and ran out of the family room, toward the front of the house.

Ducking the stool, I said, "Ma'am, I'm sorry about the mess," and I went looking for Penny's killer.

Behind me, the woman screamed, "Stevie, lock your door! Stevie, lock your door!"

By the time I reached the foot of the open stairs in the foyer, Harlo had climbed to the landing.

I saw why he had been drawn upward instead of fleeing the house: At the second floor stood a wide-eyed little boy, about five years old, wearing only undershorts. Holding a blue teddy bear by one of its feet, the kid looked as vulnerable as a puppy stranded in the middle of a busy freeway

Prime hostage material.

"Stevie, lock your door!"

Dropping the blue bear, the kid bolted for his room.

Harlo charged up the second flight of stairs.

Sneezing out the tickle of chlorine and the tang of burning strawberry jam, dripping, squishing, I ascended with somewhat less heroic flair than John Wayne in Sands of Iwo jima .

I was more scared than my quarry because I had something to lose, not least of all Stormy Llewellyn and our future together that the fortune-telling machine had seemed to promise. If I encountered a husband with a handgun, he'd shoot me as unhesitatingly as he would Harlo.

Overhead, a door slammed hard. Stevie had done as his mother instructed.

If he'd had a pot of boiling lead, in the tradition of Quasimodo, Harlo Landerson would have poured it on me. Instead came a sideboard that evidently had stood in the second-floor hall, opposite the head of the stairs.

Surprised to discover that I had the agility and the balance of a monkey, albeit a wet monkey, I scrambled off the stairs, onto the railing. The deadfall rocked past step by step, drawers gaping open and snapping shut repeatedly, as if the furniture were possessed by the spirit of a crocodile.

Off the railing, up the stairs, I reached the second-floor hall as Harlo began to break down the kid's bedroom door.

Aware that I was coming, he kicked harder. Wood splintered with a dry crack, and the door flew inward.

Harlo flew with it, as if he'd been sucked out of the hall by an energy vortex.

Rushing across the threshold, pushing aside the rebounding door, I saw the boy trying to wriggle under the bed. Harlo had seized him by the left foot.

I snatched a smiling panda-bear lamp off the red nightstand and smashed it over Harlo's head. A ceramic carnage of perky black ears, fractured white face, black paws, and chunks of white belly exploded across the room.

In a world where biological systems and the laws of physics functioned with the absolute dependability that scientists claim for them, Harlo would have dropped stone-cold unconscious as surely as the lamp shattered. Unfortunately this isn't such a world.

As love empowers some frantic mothers to find the superhuman strength to lift overturned cars to free their trapped children, so depravity gave Harlo the will to endure a panda pounding without significant effect. He let go of Stevie and rounded on me.

Although his eyes lacked elliptical pupils, they reminded me of the eyes of a snake, keen with venomous intent, and though his bared teeth included no hooked or dramatically elongated canines, the rage of a rabid jackal gleamed in his silent snarl.

This wasn't the person whom I had known in high school so few years ago, not the shy kid who found magic and meaning in the patient restoration of a Pontiac Firebird.

Here was a diseased and twisted bramble of a soul, thorny and cankerous, which perhaps until recently had been imprisoned in a deep turning of Harlo's mental labyrinth. It had broken down the bars of its cell and climbed up through the castle keep, deposing the man who had been Harlo; and now it ruled.

Released, Stevie squirmed all the way under his bed, but no bed offered shelter to me, and I had no blankets to pull over my head.

I can't pretend that I remember the next minute with clarity. We struck at each other when we saw an opening. We grabbed anything that might serve as a weapon, swung it, flung it. A flurry of blows staggered both of us into a clinch, and I felt his hot breath on my face, a spray of spittle, and heard his teeth snapping, snapping at my right ear, as panic pressed upon him the tactics of a beast.