“You want a bite?” Mike asked, holding his hot dog out to me.

“Thanks, I had lunch at my desk.” I took a napkin from his hand and wiped the mustard from the corner of his mouth.

Mike grinned at me. “The guy must be a real gent if you’re cleaning me up for him.”

“Very upper-crust, this Mr. Herrick. He’s English, he’s rich, and he’s very proper. I thought it would be refreshing for him to meet you.”

“Four fifty-five Central Park West. If he’s so rich, how come he’s living in the DMZ?” The area that bordered the park on the Upper West Side, north of Ninety-sixth Street, has seen more than its share of violent crime.

“According to the search I did today, when that landmark building was renovated and apartments went on the market three years ago,” I said, “Alger Herrick paid eight million dollars for the most coveted space in the joint.”

“And just seven years ago,” Mike said, shaking his head, “it was like a big old haunted house. The deadbeat hotel next door was a crack den and it was worth your life to walk down the block without being robbed by junkies or hit up by prostitutes.”

“So you know the building?”

“Had a nightmare of a case in four fifty-five back then. Three teenage boys from the ’hood killed up on the third floor, execution style, ’cause they were playing in there and witnessed a buy. The place had such a spooky history, most of the neighbors would cross the street rather than pass by too close to it. Only things inside were stray cats, dead pigeons, and half-dead crackheads.”

“I’d never heard of it until I just read the story about Herrick.”

“It was the New York Cancer Hospital in the 1880s,” Mike said. “The first one of its kind in the country to devote itself to the care of cancer patients.”

“The photo of it online looks more like a French château. The article said it was built with money from the Astor family. I guess they really did round up a load of real estate.”

“Wait till you see it. It’s got turrets on each side, round towers like in a castle,” Mike said. “The architect actually designed them on the theory that germs and dirt wouldn’t collect in corners. I can’t exactly say we had a guided tour, but Peterson and I got to know every nook and cranny in the place. It was the predecessor to today’s Memorial Hospital on the East Side.”

Mike’s late fiancée, Valerie Jacobsen, had been treated at Memorial a couple of years before-successfully-for breast cancer, only to be killed in a skiing accident. During those months, he had applied himself to learning as much about the disease as he knew about military history.

“And now it’s been transformed into elegant co-op apartments,” I said. “Maybe it’ll bring the rest of the neighborhood along with it.”

“Everything in New York used to be something else,” Mike said, tossing his trash into a pail on the corner as we waited for the light to change. “These old buildings have stories, Coop. They’re here to tell us who we were, who we used to be.”

“Herrick’s home seems to have mostly sad stories.”

“The mother of one of the boys who was killed there became a one-woman campaign to clean it up. Learned everything there was to know about its history. She told me she used to sit in the same desolate room where her kid was offed, just staring out at the park, thinking about how many people had come to the end of their lives in that forsaken place.”

“Back when it was built,” I said, “cancer was incurable. Treatment was just palliative.”

“Patients went to that hospital to die, eased by morphine and champagne, Sunday carriage rides in the park,” Mike said. “Story was that the hospital whiskey bill was higher than the one for medical supplies. Even Marie Curie came to visit.”

“She did?” I asked as we crossed the broad street, dodging taxis and buses, to get to Mike’s car.

“The Curies discovered radium in 1898, and doctors here pioneered the first techniques to burn cancers away with it. The largest repository of radium in the country was kept in a steel vault right in that building.”

“I don’t know that I could live in a place like that,” I said. “Too many ghosts.”

“Life goes on,” Mike said. “The Octagon-the old lunatic asylum on Roosevelt Island-has been turned into a housing development, and the building where more than a hundred people died in the Triangle Waist Company fire in 1911 is a biology lab at NYU now. Like a phoenix from the ashes.”

I had just cleared the passenger seat of half a dozen empty soda cans, a tie, a book on the Crimean War, and a gross of Tic-Tac boxes when I heard Mike’s beeper go off.

He looked at the display and slammed the car door. “It’s Peterson.”

My cell was in my hand. I speed-dialed Mike’s boss and handed him the phone.

“Hey, Loo, what’s up?” Mike listened to the answer. “Got it. Yeah, she just bought me lunch at the medical examiner’s outdoor café. We’re on it.”

“Detour?” I asked.

“Quick stop on Ninety-third Street,” Mike said.

“Tina’s apartment? Why?”

“Because Billy Schultz played hookey from his office today. He’s working from home.”

“So?”

Mike was driving up First Avenue, weaving between cars to catch the lights while he talked. “Precinct guys spent the morning canvassing the buildings that face the garden behind the apartment. Got a rear-window thing going on. Remember Billy told us he hadn’t seen much of Tina since the summer? Well, the little old lady who takes the fresh air on her fire escape saw Billy out back with Tina over the weekend. Saturday, right around dusk.”

“Doing what?”

“Digging.”

“You mean gardening?”

“I would have said it if that’s what I meant. She says digging. With a great big shovel and mounds of dirt. No pansies, no tulips, no vegetables.”

“Why didn’t he tell us?” We were cruising past the United Nations, and Mike put on his whelper to cut a course through the slow-moving traffic. “Did you see any disturbance in the garden?”

“Actually, Coop, I was distracted by the broad on the floor with the bad headache. I thought there was a messy patch in the yard, and I just figured it was where the perp pulled the armillary out of the ground to whack her. Anyway, Crime Scene will have photos,” Mike said. “Peterson’s got a uniform outside his apartment, rope-a-doping him into answering questions about all the other tenants till we get there. And I buried the lead.”

“What’s that?” I held the dashboard as Mike slammed on the brakes to avoid an Asian deliveryman, then accelerated again.

“That gas mask the cops picked up a few doors away from the building the night Barr was attacked?” Mike asked.

“Don’t look at me. Look at the road,” I said. “What about it?”

“Preliminary on the DNA inside the mask. There’s a mixture, of course,” Mike said. “I’d expect that with something like a mask-especially if it isn’t brand new. And one of the profiles matches Billy Schultz.”

“Are you serious? I never thought of him that way for a minute. He was wearing the damn thing?”

“Skin cells, sweat. I don’t know what else they got.”

Once we passed the turn-off for the Fifty-ninth Street Bridge, we made the left onto Ninety-third Street in less than three minutes.

I could see an officer talking to Schultz on the sidewalk as we pulled up in front of the building. He looked over when he heard the car door shut and started up the steps as Mike approached.

“Yo, Billy,” Mike said. “I need a couple of minutes of your time.”

Schultz was wearing a plaid flannel shirt, sleeves rolled up, and he frowned as he checked his watch before telling Mike that he had to get back upstairs for a conference call. “I can’t talk to you now.”

“A guy could get a complex. Only person who’s ever happy to see me is my mother,” Mike said. “It’s just a little thing.”

“Really, I’ve got to make a call.”

“This Minerva Hunt thing’s got me puzzled.” Mike was doing his best Columbo imitation, a look of complete befuddlement on his face. He seemed too dense to be able to figure out much of anything. “When you phoned 911, you told the operator you thought the dead woman was Minerva Hunt, right?”