Nervous laughter burst from several people in the room. Louise Reynolds, a young community support team officer, was shamefaced. “Sorry, boss. When was he last seen before the incident?”

“A good point. I don’t have that information, but perhaps you could find out. We did a door-to-door of the immediate neighbors last night, but we need to expand that now. Get that sorted, would you, this morning?”

“Yes ma’am. Also …”

“Yes?”

“I did notice something. Might not be relevant.”

“Go on.”

“The window, on Gregor’s flat. It’s overlooked by the window of one of the West Block flats. Is it worth asking the tenants if they’ve seen anything?”

“Good idea,” said Harper, concentrating on not glancing at Atkinson, whose eyes she could feel on the side of her face. “You might need to knock on all of the seventh-floor flats …”

“I looked at a floor plan. I know which one it is. Apartment 7B.”

Ruby’s place. Of course it was. Harper could barely control the nervous tic in her cheek. It wouldn’t be anything to do with Ruby, though. There was no need to mention the connection. Was there? She said, “Great. I’ll follow that up, then.”

“You will?” said Atkinson. She looked straight at him. He was frowning, probably because, as senior investigating officer, she should have assigned a junior officer to take a statement.

Joanna wasn’t going to be questioned. “Anything to add, Steve?”

It took him a couple of seconds to gather his thoughts. “Um, yep. We’ve managed to get a good likeness of the woman we suspect was living in Franks’s apartment with the child. This is a still from the train station CCTV.”

The woman in the picture had her hood up, as she had in the footage from the estate, but her pale face had been captured finally. The dark eyes seemed haunted.

“What’s she looking at?” asked Jo. In the wide shot the woman stood away from the other passengers, holding the child tightly against her chest. She stared intensely into the middle distance, as if frightened of whatever it was that she could see. But there was nothing there.

“We’ve circulated the picture to news outlets, and this morning there will be an appeal for witnesses. At this point we’re thinking child protection, mainly. We don’t know the name or circumstances, but we need to find this woman and child, to check there’s nothing amiss.”

Another young officer said, “She’s not a suspect?”

“We need to rule her out.”

Harper said, “In terms of evidence. Did anyone manage to find any images of this woman inside the actual building?”

“Not yet,” said Atkinson. “But we got this a few minutes ago.”