What Balfour and his lawyer wanted to know was why the police hadn’t seen fit to share with them the story of the dolls, or the information about the German student and the Internet game.

What the Chief Constable wanted to know was what Carswell intended doing about it.

And what Carswell himself wanted was blood.

His official car, driven by his acolyte DI Derek Linford, drew up in front of a station already crowded with officers. Everyone who had worked or was currently working on the Balfour case – uniforms, CID, even the forensic team from Howdenhall – had been ‘requested’ to attend the morning meeting. Consequently, the briefing room was packed and stifling. Outside, the morning was still recovering from overnight sleet, the pavement damp and chilling to the feet as Carswell’s leather-shod soles stamped across it.

‘Here he comes,’ someone said, watching as Linford, having opened Carswell’s door for him, now closed it and, showing a slight limp, walked back round to the driver’s side. There was a sound of folding paper as the fresh tabloids – each copy the same title, each open at the same gathering of pages – were closed and put out of sight. DCS Templer, dressed as though for a funeral, dark lines under her eyes, came into the room first. She whispered something into the ear of DI Bill Pryde, who nodded and tore the corner from a notepad, spitting into it the wad of chewing gum he’d been gnawing for the past half-hour. When Carswell himself walked in, there was a ripple of movement as officers subconsciously corrected their posture or checked their attire for obvious blemishes.

‘Is anyone missing?’ Carswell called out. No ‘good morning’, no ‘thank you all for coming’, the usual protocols forgotten. Templer had a few names for him – minor ailments and complaints. Carswell nodded, didn’t seem interested in what he was being told, and didn’t wait for her to finish the roll-call.

‘We’ve got ourselves a mole,’ he bawled, loud enough to be heard down the corridor. He nodded slowly, eyes trying to take in every face in front of him. When he saw that there were people at the back, out of staring range, he walked up the aisle between the desks. Officers had to shift so he could get through, but left enough room so that there was no possibility he might brush against them.

‘A mole’s always an ugly little thing. It lacks vision. Sometimes it has big greedy paws. It doesn’t like to be exposed.’ There were flecks of saliva either side of his mouth. ‘I find a mole in my garden, I put down poison. Now, some of you will say that moles can’t help it. They don’t know they’re in someone’s garden, a place of order and calm. They don’t know they’re making everything ugly. But they are, whether they know it or not. And that’s why they have to be eradicated.’ He paused, the silence lingering as he walked back down the aisle. Derek Linford had entered the room as if by stealth and was standing by the door, eyes searching out John Rebus, the two of them recent enemies …