Rebus frowned. ‘Day off?’

‘Not officially. The switchboard tried his home, no answer.’

‘Is that where you’re headed?’

Grogan nodded.

Rebus didn’t ask if they could tag along; Grogan would only say no. But once the convoy was moving, no one would notice an extra car at the tail.

He got back into the Peugeot and told Jack about it, while Jack reversed and found a parking spot out of the way. They watched the police cars execute three-point turns and head back out of the estate, then eased their way in behind the last of them.

They headed north over the Dee and along Anderson Drive, passing more buildings belonging to Robert Gordon’s University, and several oil company HQs. At last they headed off Anderson Drive, past Summerhill Academy, and into a tight maze of suburban streets with green-field sites beyond.

A couple of the cars left the convoy, probably to circle around and come at Davidson’s house from the other direction, blocking him in. Brake lights came on, the cars stopping in the middle of the road. Doors opened, officers appearing. Quick confabs, Grogan issuing orders, pointing to left and right. Most eyes were on a single house, its curtains closed.

‘Reckon he’s flown?’ Jack asked.

‘Let’s find out.’ Rebus undid his seat-belt and opened the door.

Grogan was sending men to the neighbouring houses, some to ask questions, some to nip out the back door and work their way round the back of the suspect’s house.

‘Hope this isn’t a wild goose chase,’ Grogan muttered. He saw Rebus, but still barely registered his presence.

‘Men in position, sir.’

People had come out of their houses, wondering what was going on. Rebus could hear the distant chimes of an ice-cream van.

‘Armed Response Unit standing by, sir.’

‘I don’t think we’ll need them.’

‘Right you are, sir.’

Grogan sniffed, ran a finger under his nose, then selected two men to go with him to the suspect’s door. He pressed the bell, and there was a collective holding of breath while they waited. Grogan rang again.

‘What can they see round the back?’

One of Grogan’s men radioed to ask. ‘Curtains are closed upstairs and down, no sign of life.’

Just like at the front.

‘Buzz a JP, say we need a warrant.’

‘Right, sir.’

‘And meantime, take a sledgehammer to that bloody door.’

The officer nodded, gave a signal, and a car boot was opened. Inside was like the back of a builder’s van. Out came the sledgehammer. Three blows and the door was open. Ten seconds later there were cries for an ambulance. Ten seconds after that, someone suggested a hearse instead.

Jack was a good copper: the boot of his car held scene of crime equipment, including overshoes and gloves, and the all-over plastic boilersuits which made you look like a walking condom. Officers were being kept out of the house so as not to contaminate the scene. They stood crammed in the doorway, trying to see what they could. When Rebus and Jack stepped forward, no one recognised them, so took them for forensics. The crowd parted for a moment, and both men were inside.