‘I agree with you,’ said Denise. ‘I understand what you are saying — and I don’t mean to be rude, but there’s an important principle here that I would like you to acknowledge.’

The consultant looked up, his expression indicating surprise but a grudging respect for Denise.

‘Your concern is for the welfare of these two children,’ said Denise. ‘And you’re right: an experienced detective will naturally exert psychological pressure during an interview. Two big guys in suits are scary. Guilt is scary. These children are suffering fear and guilt — that’s not the way to ease their pain. I entirely understand that you would not want them interviewed. In fact, normally I would support it, Doctor. There is nothing more important than the welfare of these two children.’

‘Thank you, Dr Levene.’

‘But here’s my point,’ Denise continued. ‘These two children, we believe, have lost their mother. What I want to offer, Doctor, is a chance for them to close this primary trauma, not shy away from it. I want them to understand who killed their mother and why, then you can work on the secondary trauma, their fears. They have seen irrational violence. We need to show them that a man, who was very sick, and very wrong, did this thing and is now locked up. Until we can tell them this story, they will not heal.’

Denise stopped and held the psychologist’s gaze. When she saw the movement in his throat, the tiny muscle twitch in his eye, she knew she had him.

‘So, Doctor, for the welfare of the children, I am suggesting that we need to know how their mother died and who killed her. If we find these two simple facts, we can begin to piece their world back together.’

She saw the consultant swallow.

‘First, though, you will need to know what I am asking for. I need three sessions, each lasting thirty minutes. I will ask them a single question about the event. I won’t repeat it. I’ve written the question here for you.’ Denise handed the piece of paper to the consultant. He read it, nodded, then passed it around the table. He waited, looked at each set of eyes.

‘Okay, Dr Levene. I’ll give you the three sessions, but no one else speaks to the children.’

‘No one but me.’ She reached out her hand and the consultant shook it. He held it a moment too long, just as she’d expected.

Children’s Psychiatric Unit, Harlem

March 12, 9.00 a.m.

The room was a small ugly square. It had the lack of generosity and aesthetics of every municipal building. Denise had asked for the three sessions to be held in a single morning. It wasn’t ideal. It would have been better to hold them on consecutive days, but time was too important.

The first two sessions had gone reasonably well. The kids didn’t utter a word, but the odd nod and their facial expressions showed Denise that they were paying attention.

The third session was the important one. Harper sat at the back, watching, with his sketchpad open. Denise talked about her own mother. The kids didn’t seem to care.

Denise knew she didn’t have long to get a connection with them. She took her question out and smiled at the two kids. ‘We’ve got to go now, unless there’s something more you want to tell us?’ She searched their faces. They had no idea what to say or why.

She toyed with the question in front of her. She turned it in her hand, let the time slip by. Finally, she looked up.

‘Is there anything you can tell us about what happened in the alley that might help us catch the man who hurt your mother?’

She waited. The boy’s face seemed to show thought. His eyes moved around. The girl didn’t even look up. She hadn’t once held Denise’s gaze.

Nothing. Two minutes passed. They had all said that the boy knew something. He gave out more clues with his non-verbal communication, as if he needed to get this horror out of his system.

In the corner, Harper sketched a falcon from memory, the pylon below. Denise watched the children closely, then spotted something. A small, perhaps insignificant thing. She honed in on the girl and flicked a quick look over her shoulder. The girl was watching Harper.

What was interesting her? Denise waited another two minutes. Again, the girl’s eyes rested beyond Denise’s left shoulder.

Denise leaned back in her chair and reached her arm out. ‘Can I have your sketch?’

Harper let her take his notebook. Denise started to look through the pictures, concealing them from the girl. She needed to know what was interesting her. Another two minutes passed. The second hand on the white clock-face was slipping by. She didn’t have much time left. Then it happened again. The girl looked up through her bangs. She looked first at Tom but then quickly searched the room and rested her eyes on the book in Denise’s hand.

It was not Tom she was interested in, it was the book. Denise placed it in front of her. She slowly lifted her eyes again and stared at the picture of a falcon. There was a moment of apprehension, then she reached out and touched the picture of the bird.

‘Do you have the crime-scene sketches in here?’ said Denise.

‘Few pages back.’

Denise took up the book and flicked back to the scene of the alleyway. It was drawn several times, from different angles. She chose the one from the perspective of the far end where the dumpster was. She placed it in front of the children.

They both stared at the alleyway. The little girl reached out her hand and touched it.

‘Tom, draw a figure in the alleyway.’

Harper moved across and sketched a person standing in the alleyway. The two children watched intently.

‘Okay, draw another figure.’

Tom drew another figure. The mother this time, wearing a black suit. The little girl’s hand reached out and touched the figure.

‘Good. Now draw a third figure.’

Harper moved in again and drew a third figure next to the first. The girl’s hand darted out and she started to shake her head vigorously. Harper took his pen and scribbled over it. The girl calmed.

‘Okay, this is good. It’s one guy.’ She looked at Tom. ‘Draw me the dumpster.’

He did. The children looked at it. Presumably, they had heard people coming up the alleyway and had scurried behind it.

‘Draw them. Draw the boy watching but the girl hiding her eyes.’

Harper drew, but the girl’s head started shaking again. Tom sketched the boy hiding his eyes. He then showed the girl watching. There was no interference. ‘It was the girl who saw what happened,’ said Denise. ‘No one’s ever asked her. We’ve all just presumed the boy saw it while the girl hid.’

Harper drew a gun in the man’s hands. The girl pointed to the page. Harper seemed to understand and changed the man’s arm to point to the ground. Then the little girl pointed to the sketch of her mother and then at the man’s feet. It had been Harper’s instinct that she’d been kneeling and polishing his boots. He drew. The girl rested her finger on the man.

‘What?’

She took the notebook and turned a few pages back. She found the bird and pointed at it.

Harper and Denise stared for a moment. They didn’t understand. The girl then turned back to the alleyway and she pointed to the man.

‘A tattoo?’ said Denise.

Harper drew a small bird on his arm. The girl nodded. Harper then drew three quick sketches of birds. She chose the picture of the American Eagle, its head to the side, its wings arched.

‘Unbelievable,’ said Denise. ‘She was ten yards away.’

Harper looked at the girl. Her features were like her mother’s. Blue eyes, freckled cheeks. He drew her mother from memory and put it in front of her. The girl stared down. It had been only a day since the children had seen her face. Her brother looked away, biting his thumb, curling all his limbs inwardly.

The girl’s hand reached out and touched the face on the page. Harper handed her the pencil. She took Harper’s pencil and wrote two numbers beside her mother’s face. Two number 8s, side by side. Then she looked up at Denise and Harper. ‘Did he say anything?’ said Denise.