Across the top of the car, Atkinson followed her eyes to the seventh floor of the North Block.

“You’re not thinking what I think you’re thinking, are you?”

“I just want a quick look.”

“You can’t go in there now. They’ve sealed it up to preserve the evidence.”

“I had no idea Ruby was involved when we went in before. There might be something I missed.” Jo pocketed her keys and started toward the brightly lit lobby of Gregor’s building. “Go home, Steve,” she said, but when she reached the door and he was right behind her, she was secretly pleased.

At the apartment door, she ripped the yellow police tape from the frame and pushed the key into the lock. As she did so, she noticed that the utilities cupboard in the corridor to the right of the door was ajar. There was a padlock lying open on the floor, its key still inserted. Inside the cupboard there was nothing but the water stopcock, the energy meters, and a space underneath with a gap in the dust, as if something that had been there for a long time had been recently removed.

Not knowing what or if this meant anything, she tucked the information away, cataloging it along with the other scraps she had, none of which seemed to her to be connected yet, though she knew they had to be. Cases came together for Harper all at once like illusions, puzzle pieces falling randomly until she took a step in a different direction and suddenly it would come to her, the links, the gaps, shining a light on it all so she could see the way through. She turned each fact over, searching for the kinks, the points at which each one joined the rest: first, a child abandoned on the seafront; a mysterious woman disappearing; Ruby convincing the Social Services to let her take the woman’s child, then disappearing herself. The state of Ruby’s flat. The last phone call they’d had, Ruby’s tone of voice when talking about the people she’d met. The neighbor, who thought Gregor lived alone. The invisible child, with no records, slipping through the cracks. The invisible mother, Constance. Where did Ruby fit into the picture? Something in Franks’s flat might tell her. But she had to be quick. Atkinson was on her side, but the fingerprint evidence would point the investigation at the name Ruby Harper soon enough, no matter how hard she tried to obstruct it.