He had been on his way back to Silver’s after a night and a day and half a night on the roofs. Sleeping up there, drinking orange juice and eating cold pizza on the tall terraces of the Bayswater Road after scaling the asymmetrical heights of Park Lane. He’d walked along the canal from Paddington Basin to the bridge at the Paddington Stop and then climbed onto the roof of a terrace in Formosa Street, some builder having thoughtfully left a ladder behind for his use. Wim never admitted to physical tiredness, he never admitted to anything, come to that, but by the time he had climbed the scaffolding onto the gable end of Torrington Gardens, he paused to drink the water he had with him and to eat a bar of Cadbury’s Whole Nut chocolate. Then he lay on the slope of the mansard and edged his way along. Each time he came to a dormer he hung his head down over its lintel and looked through the topmost pane of glass. It was dark outside, the feeble orange moon drifting in and out of cloud masses, but bright with light inside except in those flats where the occupants had already gone to bed. Some of the residents used the dormer room as a bedroom but in all but one of these the curtains were drawn. In the odd room out, where there were no curtains to draw, a lone old Chinese man in striped pajamas slept on a futon, lying on his back, his arms outflung. The time was just past eleven-thirty.

Wim, apparently, observed all this with interest. It was from the fifth window from the Peterborough Avenue end that he saw the missing couple. They were sitting opposite each other across a table, holding hands on its surface and talking. The window was closed and what they said was inaudible. The positions they had chosen to sit in were such that, in order to see the face at the window, the man would have had to turn his head to the left almost in a half-circle and the woman hers sharp right. Only a noise at the window would have alerted them to move like this and Wim never made a noise.

He watched them for a few minutes, half-expecting the boy Jason to come into the room. But it was too late for a child to be up. The man was fully dressed but the woman wore a dressing gown over a long nightdress. Her hair was fair, dry, and brittle-looking, her face strained and networked with lines. Andrew Lane was less easy to identify because before he had disappeared with Alison Barrie and the child he had worn a beard. But the square brow and the thick black circumflex eyebrows were unmistakable.

“Have they been there all the time?” Silver asked. “It’s been months. Since March, hasn’t it?”