He probably had done the same thing when, as a boy living on this street, he had delighted in the first snow of the season.

He has no memories of snowmen, snowball battles with other kids, or sledding. Though he must have done those things, they have been expunged along with so much else, and he has been denied the sweet joy of nostalgic recollection.

A flagstone walkway traverses the winter-brown front lawn.

He climbs three steps and crosses the deep porch.

At the door, he is paralyzed by fear. His past lies on the other side of this threshold. The future as well. Since his sudden self-awareness and desperate break for freedom, he has come so far.

This may be the most important moment of his campaign for justice. The turning point. Parents can be staunch allies in times of trouble.

Their faith.

Their trust. Their undying love. He is afraid he will do something, on the brink of success, to alienate them and destroy his chances for regaining his life. So much is at stake if he dares to ring the bell.

Daunted, he turns to look at the street and is enchanted by the scene, for snow is falling much faster than when he approached the house. The flakes are still huge and fluffy, millions of them, whirling in the mild northwest wind. They are so intensely white that they seem luminous, each lacy crystalline form filled with a soft inner light, and the day is no longer dreary. The world is so silent and serene two qualities rare in his experience-that it no longer seems quite real, either, as if he has been transported by some magic spell into one of those glass globes that contain a diorama of a quaint winter scene and that will fill with an eternal flaky torrent as long as it is periodically shaken.

That fantasy is appealing. A part of him yearns for the stasis of a world under glass, a benign prison, timeless and unchanging, at peace, clean, without fear and struggle, without loss, where the heart is never troubled.

Beautiful, beautiful, the falling snow, whitening the sky before the land below, an effervescence in the air. It's so lovely, touches him so profoundly, that tears brim in his eyes.

He is keenly sensitive. Sometimes the most mundane experiences are so poignant. Sensitivity can be a curse in an abrasive world.

Summoning all his courage, he turns again to the house. He rings the bell, waits only a few seconds, and rings it again.

His mother opens the door.

He has no memory of her, but he knows intuitively that this is the woman who gave him life. Her face is slightly plump, relatively unlined for her age, and the very essence of kindness. His features are an echo of hers. She has the same shade of blue eyes that he sees when he looks into a mirror, though her eyes seem, to him, to be windows on a soul far purer than his own.

"Marty!" she says with surprise and a quick warm smile, opening her arms to him.

Touched by her instant acceptance, he crosses the threshold, into her embrace, and holds fast to her as if to let go would be to drown.

"Honey, what is it? What's wrong?" she asks.

Only then does he realize that he is sobbing. He is so moved by her love, so grateful to have found a place where he belongs and is welcome, that he cannot control his emotions.

He presses his face into her white hair, which smells faintly of shampoo. She seems so warm, warmer than other people, and he wonders if that is how a mother always feels.

She calls to his father, "Jim! Jim, come here quick!"

He tries to speak, tries to tell her that he loves her, but his voice breaks before he can form a single word.

Then his father appears in the hallway, hurrying toward them.

Distorting tears can't prevent his recognition of his dad. They resemble each other to a greater extent than do he and his mother.

"Marty, son, what's happened?"

He trades one embrace for the other, inexpressibly thankful for his father's open arms, lonely no more, living now in a world under glass, appreciated and loved, loved.

"Where's Paige?" his mother asks, looking through the open door into the snow-filled day. "Where are the girls?"

"We were having lunch at the diner," his father says, "and Janey Torreson said you were on the news, something about you shot someone but maybe it's a hoax. Didn't make any sense."

He is still choked with emotion, unable to reply.

His father says, "We tried to call you as soon as we walked in the door, but we got the answering machine, so I left a message."

Again his mother asks about Paige, Charlotte, Emily.

He must gain control of himself because the false father might arrive at any minute. "Mom, Dad, we're in bad trouble," he tells them.

"You've got to help us, please, my God, you've got to help."

His mother closes the door on the cold December air, and they lead him into the living room, one on each side of him, surrounding him with their love, touching him, their faces filled with concern and compassion. He is home. He is finally home.

He does not remember the living room any more than he remembers his mother, his father, or the snows of his youth. The pegged-oak floor is more than half covered by a Persian-style carpet in shades of peach and green. The furniture is upholstered in a teal fabric, and visible wood is a dark red-brown cherry. On the mantel, flanked by a pair of vases on which are depicted Chinese temple scenes, a clock ticks solemnly.

As she leads him to the sofa, his mother says, "Honey, whose jacket are you wearing?"

"Mine," he says.

"But that's the new style varsity jacket."

"Are Paige and the kids all right?" Dad asks.

"Yes, they're okay, they haven't been hurt," he says.

Fingering the jacket, his mother says, "The school only adopted this style two years ago."

"It's mine," he repeats. He takes off the baseball cap before she can notice that it is slightly too large for him.

On one wall is an arrangement of photographs of him, Paige, Charlotte, and Emily at different ages. He averts his eyes from that gallery, for it affects him too deeply and threatens to wring more tears from him.

He must recover and maintain control of his emotions in order to convey the essentials of this complex and mysterious situation to his parents.

The three of them have little time to devise a plan of action before the imposter arrives.

His mother sits beside him on the sofa. She holds his right hand in both of hers, squeezing gently, encouragingly. j - To his left, his father perches on the edge of an armchair, leaning . forward, attentive, frowning with worry.

He has so much to tell them and does not know where to begin.

He hesitates. For a moment he is afraid he'll never find the right first word, fall mute, oppressed by a psychological block even worse than the one that afflicted him when he sat at the computer in his office and attempted to write the first sentence of a new novel.

When he suddenly begins to talk, however, the words gush from him as storm waters might explode through a bursting barricade. "A man, there's a man, he looks like me, exactly like me, even I can't see any difference, and he's stolen my life. Paige and the girls think he's me, but he's not me, I don't know who he is or how he fools Paige.

He took my memories, left me with nothing, and I just don't know how, don't know how, how he managed to steal so much from me and leave me so empty."

His father appears startled, and well might he be startled by these terrifying revelations. But there's something wrong with Dad's startlement, some subtle quality that eludes definition.

Mom's hands tighten on his right hand in a way that seems more reflexive than conscious. He dares not look at her.

He hurries on, aware that they are confused, eager to make them understand. "Talks like me, moves and stands like me, seems to be me, so I've thought hard about it, trying to understand who he could be, where he could've come from, and I keep going back to the same explanation, even if it seems incredible, but it must be like in the movies, you know, like with Kevin McCarthy, or Donald Sutherland in the remake, Invasion of the Body Snatchers, some thing not human, not of this world, something that can imitate us perfectly and bleed away our memories, become us, except some how he failed to kill me and get rid of my body after he took what was in my mind."

Breathless, he pauses.

For a moment, neither of his parents speak.

A look passes between them. He does not like that look. He does not like it at all.

"Marty," Dad says, "maybe you better go back to the beginning, slow down, tell us exactly what's happened, step by step."

"I'm trying to tell you," he says exasperatedly. "I know it's incredible, hard to believe, but I am telling you, Dad."

"I want to help you, Marty. I want to believe. So just calm down, tell me everything from the beginning, give me a chance to under stand."

"We don't have much time. Don't you understand? Paige and the girls are coming here with this* this creature, this inhuman thing.

I've got to get them away from it. With your help I've got to kill it somehow and get my family back before it's too late."

His mother is pale, biting her lip. Her eyes blur with nascent tears.

Her hands have closed so tightly over his that she is almost hurting him. He dares to hope that she grasps the urgency and dire nature of the threat.

He says, "It'll be all right, Mom. Somehow we'll handle it. Together we have a chance."

He glances at the front windows. He expects to see the BMW arriving in the snowy street, pulling into the driveway. Not yet.

They still have time, perhaps only minutes, seconds, but time.

Dad clears his throat and says, "Marty, I don't know what's happening here-"

"I told you what's happening!" he shouts. "Damn it, Dad, you don't know what I've been going through." Tears well up again, and he struggles to repress them. "I've been in such pain, I've been so afraid, for as long as I can remember, so afraid and alone and trying to understand."

His father reaches out, puts a hand on his knee. Dad is troubled but not in a way that he should be. He isn't visibly angry that some alien entity has stolen his son's life, isn't as frightened as he ought to be by the news that an inhuman presence now walks the earth, passing for human. Rather, he seems merely worried and* sad.

There is an unmistakable and inappropriate sadness in his face and voice. "You're not alone, son. We're always here for you. Surely you know that."

"We'll stand beside you," Mom says. "We'll get you whatever help you need."

"If Paige is coming, like you say," his father adds, "we'll sit down together when she gets here, talk this out, try to understand what's happening. Their voices are vaguely patronizing, as if they are talking to an intelligent and perceptive child but a child nonetheless.

"Shut up! Just shut up!" He pulls his hand free of his mother's grasp and leaps up from the sofa, shaking with frustration.

The window. Falling snow. The street. No BMW. But soon.

He turns away from the window, faces his parents.

His mother sits on the edge of the sofa, her face buried in her hands, shoulders hunched, in a posture of grief or despair.

He needs to make them understand. He is consumed by that need and frustrated by his inability to get even the fundamentals of the situation across to them.

His father rises from the chair. Stands indecisively. Arms at his sides. "Marty, you came to us for help, and we want to help, God knows we do, but we can't help if you won't let us."

Lowering her hands from her face, with tears on her cheeks now, his mother says, "Please, Marty. Please."

"Everyone makes mistakes now and then," his father says.

"If it's drugs," his mother says, through tears, speaking as much to his father as to him, "we can cope with that, honey, we can handle that, we can find treatment for that."

His glass-encased world-beautiful, peaceful, timeless-in which he's been living during the precious minutes since his mother opened her arms to him at the front door, now abruptly fractures.

An ugly, jagged crack scars the smooth curve of crystal. The sweet, clean atmosphere of that paradise escapes with a whoosh, admitting the poisonous air of the hateful world in which existence requires an unending struggle against hopelessness, loneliness, rejection.

"Don't do this to me," he pleads. "Don't betray me. How can you do this to me? How can you turn against me? I am your child."

Frustration turns to anger. "Your only child." Anger turns to hatred.

"I need. I need. Can't you see?" He is trembling with rage. "Don't you care? Are you heartless? How can you be so awful to me, so cruel?

How could you let it come to this?"

At a service station in Bishop, they stopped long enough to buy snow chains and to pay extra to have them buckled to the wheels of the BMW.

The California Highway Patrol was recommending but not yet requiring that all vehicles heading into the Sierra Nevadas be equipped with chains.

Route 395 became a divided highway west of Bishop, and in spite of the dramatically rising elevation, they made good time past Rovanna and Crowley Lake, past McGee Creek and Convict Lake, exiting 395 onto Route 203 slightly south of Casa Diablo Hot Springs.

Casa Diablo. House of the Devil.

The meaning of the name had never impinged upon Marty before.

Now everything was an omen.

Snow began falling before they reached Mammoth Lakes.

The fat flakes were almost as loosely woven as cheap lace. They fell in such plenitude that it seemed more than half the volume of the air between land and sky was occupied by snow. It immediately began to stick, trimming the landscape in faux ermine.

Paige drove through Mammoth Lakes without stopping and turned south toward Lake Mary. In the back seat, Charlotte and Emily were so entranced by the snowfall that, for the time being, they did not need to be entertained.

East of the mountains, the sky had been gray-black and churning.

Here, in the wintry heart of the Sierras, it was like a Cyclopean eye sheathed in a milky cataract.

The turn-off from Route 203 was marked by a copse of pines in which the tallest specimen bore scars from a decade-old lightning strike. The bolt had not merely damaged the pine but had encouraged it into mutant patterns of growth, until it had become a gnarled and malignant tower.

The snowflakes were smaller than before, falling harder, driven by the northwest wind. After a playful debut, the storm was turning serious.