But the call was from DS Latimer.

Within a minute Hobbes was at the wheel of his car.

He’d been instructed to head for the east gate to Richmond Park, the only one the park officials had left open for the police to use. A number of uniformed offers were already standing around just inside the entranceway. Hobbes wound down his window, spoke to one and was directed along an access road. On both sides the fields and trees faded away into the dark. He knew that deer roamed these woods and banks, but all he could see was the road in his headlamps.

London’s largest enclosed parkland, a vast green space.

Once he was past the Pen Ponds, it was easy to see where the activity was. A spotlight had been set up and other lights – torch beams – moved around a police van and a number of other vehicles, both marked and plain. Hobbes drew up his car and got out. He looked around, trying to find his detective sergeant, then made his way to a command post. A constable came up to him and handed him a pair of plastic gloves. ‘Evening, sir.’

It was PC James Barlow, one of the few officers Hobbes had managed to get close to during his short time at the station. The young man’s hair was plastered to his brow. It was raining heavily.

‘What’s the situation? Where’s DS Latimer?’

‘This way, sir.’ Barlow set off along a pathway. ‘Oh, that’s the couple who found it,’ he said, pointing to a man and a woman standing in the light of the police van’s open back door. The woman was holding a dog on a lead.

‘It?’

‘I mean the body, sir.’

‘The dog. More probably.’

‘What? Oh, right … yes. Of course, sniffing about.’

This was Barlow’s first major crime scene. The young PC seemed nervous – he couldn’t stop blinking when he spoke. Hobbes wondered just how much he’d seen.

They walked off the pathway into woodland. Hobbes’s shoes sank into a layer of mud. Barlow held up a length of cordon tape that stretched from one tree to another so the inspector could duck underneath.

‘We need to find out about access,’ Hobbes said. ‘To the park, I mean.’

Barlow already had the information: ‘It’s open twenty-four hours a day to pedestrians. But vehicles can’t get in after dusk.’

‘Right. Thank you. And there’s no sign of a car parked anywhere, I take it?’

‘No. Nothing at all.’

They moved on, out of the spotlight’s reach. Darkness enclosed them. This was one of the less cultivated areas of the parkland, a patch of wilderness. A ring of smaller lights had been set up and a tent erected a few yards ahead, to stop the rain getting in.

Hobbes stopped moving.

Barlow realized and stopped as well. He watched the inspector.

Hobbes’s face was blank, unforgiving. He started to move in a circle around the tent, keeping a good few yards away from that central point. His gaze took in all of the trees one by one, then the muddy ground at his feet. He seemed to be surveying every square foot of soil and plant growth.