‘Rainy is a great self-starter, and I’ve given her the task of trying to narrow down the source of these strange marks on the body that we found in the Thames. We’ve considered wire mesh, chain-link fencing and industrial walkways, even a self-made playsuit.’

‘But that wouldn’t have asphyxiated him, would it?’

‘No. Delahaye thinks there are two separate things – the force, which is probably mechanical, and the restraint that he was wrapped in.’

‘Could it be a sex thing?’

‘That’s what Rainy mentioned. Sex games gone wrong.’ He shook his head.

‘I know people do bizarre things.’ Sam giggled. ‘But I can’t get my head round this.’

A silver Peugeot with a missing hubcap crawled down Wexford Road until it reached number sixty-three. A parking space was miraculously available right outside. Two beefy men wearing hi-vis jackets and gloves and carrying paint-stained toolboxes emerged from the car. Nigel Chivers and Terry Dalton scanned the road, then walked up to the front door and rang the bell. As expected, there was no reply. Chivers crouched down and inspected the lock. ‘Five lever mortice,’ he said, and shook his head. ‘We’ll not get in here easily, at least not without leaving a mess.’

‘We don’t want to leave a mess, obviously, Nige,’ Dalton said, keeping his eye on the street behind them. ‘Don’t want anyone to know, do we?’