Commander Frances Penn's private residence was on the west side of Manhattan where I could see the lights of New Jersey on the other side of the Hudson River. She lived fifteen floors up in a dingy building in a dirty part of the city that was instantly forgotten when she opened her white front door.

Her apartment was filled with light and art and the fragrances of fine foods. Walls were whitewashed and arranged with pen-and-ink drawings and abstracts in watercolor and pastel. A scan of books on shelves and tables told me that she loved Ayn Rand and Annie Leibovitz and read numerous biographies and histories, including Shelby Foote's magnificent volumes on that terrible, tragic war.

'Let me take your coat,' she said.

I relinquished it, gloves and a black cashmere scarf I was fond of because it had been a gift from Lucy.

'You know, I didn't think to ask if there's anything you can't eat,' she said from the hall closet near the front door. 'Can you eat shellfish? Because if you can't, I have chicken.'

'Shellfish would be wonderful,' I said.

'Good.' She showed me into the living room, which offered a magnificent view of the George Washington Bridge spanning the river like a necklace of bright jewels caught in space. 'I understand you drink Scotch.'

'Something lighter would be better,' I said, sitting on a soft leather couch the color of honey.

'Wine?'

I said that would be fine, and she disappeared into the kitchen long enough to pour two glasses of a crisp chardonnay. Commander Penn was dressed in black jeans and a gray wool sweater with sleeves shoved up. I saw for the first time that her forearms were horribly scarred.

'From my younger, more reckless days.' She caught me looking. 'I was on the back of a motorcycle and ended up leaving quite a lot of my hide on the road.'

'Donorcycles, as we call them,' I said.

'It was my boyfriend's. I was seventeen and he was twenty.'

'What happened to him?'

'He slid into oncoming traffic and was killed,' she said with the matter-of-factness of someone who has freely talked about a loss for a long time. 'That was when I got interested in police work.' She sipped her wine. 'Don't ask me the connection because I'm not sure I know.'

'Sometimes when one is touched by tragedy he becomes its student.'

'Is that your explanation?' She watched me closely with eyes that missed little and revealed less.

'My father died when I was twelve,' I simply said.

'Where was this?'

'Miami. He owned a small grocery store, which my mother eventually ran because he was sick many years before he died.'

'If your mother ran the store, so to speak, then who ran your household while your father lingered?'

'I suppose I did.'

'I thought as much. I probably could have told you that before you said a word. And my guess is you are the oldest child, have no brothers, and have always been an overachiever who cannot accept failure.'

I listened.

'Therefore, personal relationships are your nemesis because you can't have a good one by overachieving. You can't earn a happy love affair or be promoted into a happy marriage. And if someone you care about has a problem, you think you should have prevented it and most certainly should fix it.'

'Why are you dissecting me?' I asked directly but without defensiveness. Mostly, I was fascinated.

'Your story is my story. There are many women like us. Yet we never seem to get together, have you ever noticed that?'

'I notice it all the time,' I said.

'Well' - she set down her wine - 'I really didn't invite you over to interview you. But I would be less than honest if I told you that I didn't want an opportunity for us to get better acquainted.'

'Thank you, Frances,' I said. 'I am pleased you feel that way.'

'Excuse me a minute.'

She got up and returned to the kitchen. I heard a refrigerator door shut, water run and pots and pans quietly bang. Momentarily, she was back with the bottle of chardonnay inside an ice bucket, which she set on the glass coffee table.

'The bread is in the oven, asparagus is in the steamer, and all that's left is to saute the shrimp,' she announced, reseating herself.

'Frances,' I said, 'your police department has been on-line with CAIN for how long now?'

'Only for several months,' she replied. 'We were one of the first departments in the country to hook up with it.'

'What about NYPD?'

'They're getting around to it. The Transit Police have a more sophisticated computer system and a great team of programmers and analysts. So we got on-line very early.'

'Thanks to you.'

She smiled.

I went on, 'I know the Richmond Police Department is on-line. So are Chicago, Dallas, Charlotte, the Virginia State Police, the British Transport Police. And quite a number of other departments both here and abroad are in the process.'

'What's on your mind?' she asked me.

'Tell me what happened when the body of the unidentified woman we believe Gault killed was found Christmas Eve. How was CAIN a factor?'

'The body was found in Central Park early in the morning, and of course I heard about it immediately. As I've already mentioned, the MO sounded familiar, so I entered details into CAIN to see what came back. This would have been by late afternoon.'

'And what came back?'

'Very quickly CAIN called our VICAP terminal with a request for more information.'

'Can you recall exactly what sort of information?'

She thought for a moment. 'Well, let's see. It was interested in the mutilation, wanting to know from which parts of the body skin had been excised and what class cutting instrument had been used. It wanted to know if there had been a sexual assault, and if so, was the penetration oral, vaginal, anal or other. Some of this we couldn't know since an autopsy had not yet been performed. However, we did manage to get other information by calling the morgue.'

'What about other questions?' I asked. 'Did CAIN ask anything that struck you as peculiar or inappropriate?'

'Not that I'm aware of.' She regarded me quizzically.

'Has CAIN ever sent any messages to the Transit Police terminal that have struck you as peculiar or confusing?'

She thought some more. 'We've entered, at the most, twenty cases since going on-line in November. Rapes, assaults, homicides that I thought might be relevant to VICAP because the circumstances were unusual or the victims were unidentified.

'And the only messages from CAIN that I'm aware of have been routine requests for further information. There has been no sense of urgency until this Central Park case. Then CAIN sent an Urgent mail waiting message in flashing bold because the system had gotten a hit.'

'Should you get any messages that are out of the ordinary, Frances, please contact Benton Wesley immediately,'

'Would you mind telling me what it is you're looking for?'

'There was a breach of security at ERF in October. Someone broke in at three in the morning, and circumstances indicate Gault may have been behind it.'

'Gault?' Commander Perm was baffled. 'How could that have happened?'

'One of ERF's system analysts, as it turned out, was connected to a spy shop in northern Virginia that was frequented by Gault. We know this analyst - a woman - was involved in the break-in, and the fear is that Gault put her up to it.'

'Why?'

'What wouldn't he like better than to get inside CAIN and have at his disposal a database containing the details of the most horrendous crimes committed in the world?'

'Isn't there some way to keep him out?' she asked. 'To tighten security so there is no way he or anyone else can slip through the system?'

'We thought that had been taken care of,' I replied. 'In fact, my niece, who is their top programmer, was certain the system was secure.'

'Oh yes. I think I've heard about your niece. She's really CAIN's creator.'

'She has always been gifted with computers and would rather be around them than most people.'

'I'm not sure I blame her. What is her name?'

'Lucy.'

'And she's how old?'

'Twenty-one.'

She got up from the couch. 'Well, maybe there's just some glitch that is causing these weird messages you're speaking of. A bug. And Lucy will figure it out.'

'We can always hope.'

'Bring your wine and you can keep me company in the kitchen,' she said.

But we did not get that far before her telephone rang. Commander Penn answered it and I watched the pleasant evening drain from her face.

'Where?' she quietly said, and I knew the tone of voice quite well. I recognized the frozen stare.

I was already opening the hall closet door to fetch my coat when she said, I'll be right there.'

Snow had begun drifting down like ashes when we arrived at the Second Avenue subway station in the squalid section of lower Manhattan known as the Bowery.

Wind howled and blue and red lights throbbed as if the night were injured, and stairs leading into that hellhole had been cordoned off. Derelicts had been herded out, commuters had been detoured, and news vans and cars were arriving in droves because an officer with the Transit Police Homeless Unit was dead.

His name was Jimmy Davila. He was twenty-seven. He had been a cop one year.

'You better put these on.' An officer with an angry, pale face handed me a reflective vest and surgical mask and gloves.

Police were pulling flashlights and more vests out of the back of a van, and several officers with darting eyes and riot guns flashed past me down the stairs. Tension was palpable. It pulsed in the air like a dark pounding heart, and the voices of legions who had come to aid their gunned-down comrade blended with scuffing feet and the strange language radios speak. Somewhere far off a siren screamed.

Commander Penn handed me a high-powered flashlight as we were escorted down by four officers who were husky in Kevlar and coats and reflective vests. A train blew by in a stream of liquid steel, and we inched our way along a catwalk that led us into dark catacombs littered with crack vials, needles, garbage and filth. Lights licked over hobo camps set up on pallets and ledges within inches of rails, and the air was fetid with the stench of human waste.

Beneath the streets of Manhattan were forty-eight acres of tunnels where in the late eighties as many as five thousand homeless people had lived. Now the numbers were substantially smaller, but their presence was still found in filthy blankets piled with shoes, clothes and odds and ends.

Grimy stuffed animals and fuzzy fake insects had been hung like fetishes from walls. The squatters, many of whom the Homeless Unit knew by name, had vanished like shadows from their subterranean world, except for Freddie, who was roused from a drugged sleep. He sat up beneath an army blanket, looking about, dazed.