The girl looked up. It was the first time she had spoken and her voice was clear and unemotional. ‘He said his name.’

Harper and Levene held their breath. ‘What was it?’ asked Denise.

‘Something I don’t remember,’ said the girl.

‘Josef Sturbe,’ said the boy. ‘I heard it.’

‘What did he say?’

‘He said, “I am Officer Josef Sturbe. Clean my boots”.’

The girl and the boy stared at them, clear-eyed.

‘It’s going to be okay,’ said Denise. ‘It’s going to be okay. Do you think you could tell us your names?’

‘Ruth Glass,’ said the girl. ‘This is Jerry. We’re both seven but I was born first.’

‘Thank you, Ruth. We’re going to go now, but we’ll find the person who did this to your mother. I am so sorry she’s been taken away.’

Denise stood up as the social workers walked in. Denise thanked them again as she walked out. Harper waved at the little girl and drew a quick smile on a face on his sketchpad. As he showed it to her, the little girl forgot herself for a single moment and smiled back.

Myrtle Avenue, Brooklyn

March 12, 4.06 p.m.

He sat outside the garage, drinking coffee from a Styrofoam cup. His eyes were fixed on the small TV screen. He’d bought every one of the papers but none of them mentioned a blue eagle from the murder. He liked reading about his dead. He liked to see how dumb they all were, how little they understood. He liked to keep the clippings about them. But he didn’t understand how someone had seen the eagle.

They’d found the body of Becky Glass a day earlier but the TV reports were now talking about the latest NYPD discovery. They were looking for a man with a blue eagle tattoo. The image they had was of a small blue eagle with its wings outstretched. It was more of an American eagle than the one on his arm, but it was still shocking to see the image in connection with the 88 Killer. It shouldn’t have happened. How did the cops have a picture of the eagle on his arm? He considered it closely.

He hadn’t removed his coat until he was alone with Becky Glass. He had waited outside the alleyway until she walked by. She looked distressed. She was searching for her children. He was an opportunist. He’d told her they were in the alleyway.

She ran in, all on her own. Stood there and looked around her. Then he put the gun against her head and told her to take off her pants.

He only wanted her to do that in order to remove her underwear. It was important that she was degraded and humiliated. He had not intended to rape her. She had fought and cried and disobeyed him. He had to hit her face. He had to rip off her clothes. The attack excited him. He was ashamed. He made her kneel at his feet and wash his boots clean with her spit.

No one but the victim should have been able to see the blue eagle.

He let his mind return to his victim kneeling in front of him, thinking about angles. Perhaps someone had seen him from the street. He had pushed a large metal bin in the entrance to the alley, but someone might have looked round it.

He didn’t usually kill in the daylight, but he couldn’t help himself. It had been a mistake. He had lost control. He had only meant to trail her. He had been trailing Becky Glass for a while. He knew she had two children. They were even there with her at the interview, but they’d run off before she made it back down to the reception area. She was searching for the children. That’s why she went into the alleyway, to look for them, and that’s why he had acted. He hadn’t planned to kill her so soon, but it just overcame him and he couldn’t resist. He didn’t even bother to check to see if the children were in the alley. He had been foolish. The urge was too strong; the pressure of the press and the cops was getting to him.

He knew that Becky was a single mother. She had told him as much as he placed the gun at her head. He had listened to her pleading on behalf of her children as he dragged the clothes from her body. He hadn’t imagined for a moment that her children were watching, but, thinking logically, where would they go?

He recalled the scene. She had polished his boots. It had made him feel better. He had said he was pleased. He remembered her anxious gaze around the alley.

It was obvious and he wanted to kick himself for being so stupid. He had presumed that she was looking for help. But she had been terrified about her children witnessing the scene rather than what was happening to her. Witnesses. The children had seen him kill her. He leaned back against the garage. The children would be able to identify him. That couldn’t be allowed. That would put an end to his plans.

Museum of Tolerance, Brooklyn

March 12, 4.42 p.m.

Denise sat in the large glass atrium of the museum waiting for Aaron Goldenberg to appear. She had already scented the 88 Killer and thought she understood the way his mind worked — from the clinical bullet-hole to the forehead to the brutally angry use of barbed wire. One mind, twisted beyond normal limits, a man with a need for control — surgical control — and a deep, deep pain that needed to be screamed from the housetops. But he was losing that control. Which would make him even more dangerous.

She looked down at her notebook and took up her pen. She kept seeing the number that Ruth Glass had written on the page. She wrote the words across the top. Profile of the 88 Killer.

Denise was in the process of unpicking the killer’s mind. Like an expert unpicking a lock, she would press each lever in turn, teasing and testing until it fell in line and suddenly the whole row would be along the shear line and the lock would open. That was all she was after — the killer’s shear line.

So far, she had written: He’s male, early- to mid-thirties, gifted, but a failure in something, single, unable to form strong relationships, with a background in security or military-type work. A man without siblings, a lone child, probably with a normal-looking family, a family he felt never knew what he was, never accepted him. Possibly adopted.

She looked at the words and felt the give of the first lever of the lock. She continued to write. He’s used to being alone, it’s not a problem for him to be alone. He’s been alone his whole life, he can take it. But he needs to be understood and that’s confusing him. He feels a dual push to keep hidden but to be understood. His latest kills show an increased stress level. He is getting more extreme, his attacks becoming regular, necessary. He is not a neo-Nazi with Nazi sympathies, it is stronger, the identification almost exact. He is a Nazi.

Just then, Aaron Goldenberg appeared, holding a sheaf of papers and folders. He looked at Denise’s notebook.

‘It should say Profile of Josef Sturbe,’ he said.

Denise turned. ‘Aaron. How are you?’

‘Better now. It has been so many days with nothing to do. Now I can work.’

‘So what did you find? Is Josef Sturbe a real identity or an assumed one?’

‘I will let you know what I found out,’ said Aaron. ‘But how did Harper get on?’

‘Detective Harper has tried every database that he can find and there’s nobody coming up with that name. The Feds have nothing on him either. They think it’s a name Martin Heming uses. A pseudonym.’

‘Then they’d be wrong,’ said Dr Goldenberg. ‘Very wrong.’

Denise raised both eyebrows. ‘He’s real?’

‘Yes, Josef Sturbe is real, all right.’

‘How the hell did you find a man when the combined forces of the NYPD and FBI couldn’t?’

‘They weren’t looking in the right places.’

‘Then what are the right places? Where can we find him?’

‘We can’t find him, but we know who he is. Josef Bernard Sturbe was born in Bavaria in 1923. We don’t have any records of him until 1943 when he turns up in the Warsaw Ghetto.’