He opened his eyes, and was shocked to find he wasn’t in a bedsit in 1999. It was fifteen years later, he hadn’t listened to Nine Inch Nails for years and he was lying on the floor of an office.

He sat up, clutching his head as the pain bloomed inside his skull. He gingerly felt his cranium – a lump the size of a baby’s fist had sprung up on his forehead. Then, in a whoosh, everything came back to him. Doctor Koppler. The paperweight. Sharon Fredericks. He checked the time. He’d been out for thirty minutes. Not good.

He found his phone in his inside pocket. Carmella picked up on the third ring.

‘Carmella, I need a car to pick me up now. And get me the DCI. We’re going to need a lot of back-up – a PSU, commissioner’s reserve, all the bells and whistles, OK?’

‘I’m on it, boss.’

‘Did you bring the painkillers?’ were Patrick’s first words fifteen minutes later when Carmella arrived. She had volunteered to pick him up herself. She handed him a packet of ibuprofen and a bottle of water. He took three, thought about it, then added a fourth.

‘I ought to take you to the hospital, get you checked out.’

‘I’m fine. Please don’t fuss.’

‘I’m not fussing. I just don’t want you passing out on me. I make a terrible nurse.’

He took a swig of water, wincing again at the throbbing in his head. ‘You’ve got Koppler’s home address?’

‘Of course. The PSU should be there already. He lives a mile away, in Parsons Road.’

On the way there, Patrick filled Carmella in on what had happened in the office. ‘This is my guess. Koppler must have formed a bond with Fredericks when he was treating her. A romantic bond, most likely. She could very well be living with him. And somewhere along the line they became desperate for a child but, I’m guessing, couldn’t conceive. With Fredericks’ record she would never be able to adopt, so . . .’

His phone rang. It was DS Mike Staunton. ‘Sir, I’m at the Hollisters’ place. I’ve shown Sharon Fredericks’ photo to Bowie and he says he’s pretty sure it’s her that he saw taking Liam out of the car.’

‘Good work, Mike.’

‘One more thing, sir. We also showed her photo to Liam’s parents. Mrs McConnell recognises Sharon too. Sharon used to work as a waitress at Viva Pizza in Teddington. They used to go there every Friday with the kids. I’ve just checked with the Hartleys and they go to Viva Pizza a lot too. I haven’t asked Mr and Mrs Philips yet . . .’