Carol gave her address to the driver and leaned back against the firm leather upholstery. It was a clever move on his part, to place her in his debt without making any kind of move on her. She wanted to shout out loud to release some of the jubilation she felt. But not in front of his driver, who would doubtless report back on every nuance of her behaviour. Instead, she let her head fall back and closed her eyes. Phase one was complete. And it had gone even better than she could have hoped.

Maybe she could do this after all.

Maybe she really could walk inside someone else’s skin.

Brigadier Marijke van Hasselt walked into the detective squad room at Regio Leiden headquarters, carrying a carton of coffee and a bag of smoutebollen, the deep-fried choux pastry balls dredged with icing sugar that were her one concession to junk food. Carbs, caffeine and sugar; the only way to start the day.

Early as she was, Tom Brucke was ahead of her. He sat frowning over a pile of reports, his curly brown hair already rumpled from his constant fiddling with it. He looked up at the sound of her footsteps. His boyish face looked strained and tired, heavy lines tracking under his eyes. ‘Hey, Marijke,’ he said. ‘Fucked if I know where we’re going to find a perp for this case.’

She took an instant decision. Two heads were, as she had already proved, infinitely better than one. ‘Oddly enough, Tom, I had an idea about that last night.’ She pulled up a chair and sat at the end of his desk, tucking one leg under her.

Tom curled a tendril of hair round his index finger. ‘I’m staring at so many dead ends here, I’d seriously consider a clairvoyant,’ he said. ‘I don’t know about you, but this case is doing my head in.’

‘I keep waking up at night thinking I’m drowning,’ Marijke admitted.

Tom snorted. ‘Drowning in a sea of fucking paper,’ he said, waving a hand at the piles of reports on his desk. ‘Talk about living for your work. De Groot seems to have been on every committee he could get nominated for. He also organized an annual weekend conference for psychologists working in the same area as him. “The psychodynamics of emotional abuse,” whatever that means. The upshot of which is that half the bloody world seems to have known him. It’s a nightmare. So what’s this brilliant idea of yours?’

‘I didn’t say it was brilliant, but at least it’s something fresh to try. We’re both agreed that this is a stranger killing, right?’

‘There’s nothing in his life to indicate anything different. On the other hand, there’s no sign of forced entry. Balance of probabilities? He didn’t know his killer.’