‘Why did she call him X?’

‘It’s a domestic violence forum,’ said Denise. ‘You’re not allowed to name the bastards. That would be against the law.’

‘Seriously?’

‘Yeah, seriously. She made over four hundred posts over an eight-month period. Read some of the highlights.’

I am in an abusive relationship. My boyfriend does not let me go out or look at other men. He tries to make me admit that I have had an affair. He interrogates me for hours until I admit it, then he beats me.

X hit me twice today. Both times in the back. I don’t know what to do.

He drinks and he rapes me sometimes, but I kid myself it’s not rape, right?

X accused me of liking Jews too much and Blacks. It’s only because I’m supposed to be going to a party tomorrow. He said I’m trying to undermine him. He says I’m a slut. I said that I wasn’t. He gave me a black eye so I couldn’t go to the party.

I’m a good girl today. Will I get high fives all round? I finally broke up with X. It wasn’t as bad as I’d expected. He wasn’t happy, but he didn’t shout or scream. He just stared at me. Just stared and stared and didn’t say a thing. Not a word. Not one single word.

I got home today. X was standing outside the building again. He looked okay, but he’d obviously been drinking. I can always tell. Then he ran at me and put his hands all over me. It was only when I got inside the door that I realized that I was smeared all over with blood. I don’t even know where it came from.

Midnight. I woke up, he was at my bed. He was in my room, at my bedside. I screamed in terror. He pleaded with me to take him back. I would die if he came back. I can’t take it. He tells me that if I report him, he’ll make my life a living hell. It already is. Not one day goes by without phone calls or visits or one of his reports.

Harper read what he could. ‘No names.’

‘We can probably glean information, but it’ll take time.’

‘You mentioned Yellowstone,’ said Harper.

‘It’s the one date-posted message that tells us where our killer was for a week last year.’

‘That’s worth following up. Okay,’ said Harper. ‘We’ve got to go through Lucy’s whole electronic history. There’ll be a connection. We find she uses a credit card in some hotel, then we check every other receipt. He’s got to be there. He was with her for eight months, he can’t hide that well.’

Lock-Up, Bedford-Stuyvesant

March 14, 12.43 p.m.

The food left out in front of the shed had attracted enough of the local homeless. Not people, but stray dogs. He sat on a high pallet overlooking them. They were frail and needy. He saw the one he wanted. A little beige-brown mutt, about two foot high with a white underbelly and a nice clean snout. It was probably a hybrid of a hybrid, not a pure gene in it.

He climbed down from the pallet, took a biscuit out of his pocket and threw it to the one he wanted. The little dog looked up with big brown eyes, full of expectation and gratefulness. He threw it another biscuit.

As he walked away, the little beige dog followed him. It wasn’t fast or eager, it moved with a tentative stride. He took a third biscuit out of his pocket and held it out; this time, the dog walked across and took it from his hand.

He went inside the lock-up. The little dog followed. He shut the door. He heard Abby move in the small room behind the door. She would get her chance soon enough. The dog stopped and seemed to be aware that somehow it was no longer free. It looked at the door, at the man — and then another biscuit was thrown in its path and it forgot its instincts.

The dog looked up. A line of biscuits ran all the way across the room. It ate and moved and ate and moved, and before long, the small beige mutt was inside the room that the man had built.

The man closed the heavy acoustic door and bolted it. He moved to the Plexiglass window and looked in. The mutt had eaten the rest of its biscuits and was looking up at the window.

The man watched for a minute; there was something appealing in the dog, in its lack of knowledge. He turned, put on large yellow gloves, and opened a big round can using an old-fashioned can-opener. He poured the blue pellets into the plastic bin and then sealed the lid.

He crossed eagerly to the window. The gas was odorless and colorless. He watched for a moment, but nothing seemed to happen. He waited and watched. The dog sat, wagged its tail and barked once.

He moved closer to the window. Then the dog’s muzzle sniffed. The gas must have reached the ground level where the animal was.

The scene was unpleasant to watch, if one watched it emotionally. But if one used the scientific side of one’s nature and observed the effect of the gas, rather than reacting to the perceived pain of the dog, it was fine. Lucy was tied in the chair staring at the window. She was not detached, but then again, she was not supposed to be. He wanted to see the fear in her eyes.

The dog barked, scratched, ran a small circle and jumped up at the window. It was in agonizing pain and showed every sign of terror. But within seven minutes, it was lying on its side, almost dead.

The man raised his hand and pressed his palm to the Plexiglass. The little beige-brown mutt was still and lifeless. A harsh lesson in trusting strangers, he thought, but his experiment had worked.

North Manhattan Homicide

March 14, 4.32 p.m.

In the precinct, they reopened the cases: the brown, scratched case-files, the box-files of accumulated evidence, the database that Harper insisted on that hooked up every detail, to find links and matches. They looked back through each case slowly, letting their minds wander over the detail, trying to see what they’d overlooked. They had Lucy Steller’s phone records, Internet records, credit-card statements, bank statements and everything else besides.

On the board in front of them they had a large eight-month calendar. Every call, receipt, purchase or interaction was noted by each date. They were piecing together her life story from Internet forums, relatives, friends and the accumulated electronic data.

After just a few hours, the eight-month period was beginning to fill out. Harper stared at the board. Every time he spotted a date where Lucy was with Mr X, he had his team cross-check each receipt.

Harper had the team bring in every person who knew Lucy Steller. The interview rooms were all full and the corridors outside were lined with people. Someone had to have seen Lucy with this man, but they’d been at it for hours already and not a soul had seen him.

Denise walked up to Harper. He was staring at the cases. He had put the picture of Abby side-by-side with Lucy. He could see something. A pattern. He looked from Abby to Lucy to Capske. There was something there. What was it that was nagging away in his head? Something connected them. He looked across at the kidnapping of the children. All the unanswered questions came at once. What was the blue eagle the kids saw on the killer? How did the killer sit for hours with Capske with no one bothering him? How did he know about the safe house?

Harper’s mind clicked once, then twice. He saw a picture in his mind. He saw another. Some route through all these threads seemed to be forming, but he just couldn’t quite catch it.

‘The boot-print,’ he called to Swanson. ‘What did CSU say?’

‘Nothing at all. It’s just a boot-print. No matches on record.’

‘Jesus Christ,’ said Harper. ‘Come on, something must break here. Eddie, anything from the interviews?’

‘Nothing yet,’ shouted Eddie, ‘but we’re trying.’

Everyone was silent, working the case, poring over and over every detail.