‘You’re going to make me understand why you care so much about all these people, and let’s hope the story makes more sense than it did the first time I heard it. At the moment, the way I see it, I’ve got one in the bag: someone in the right place at the right time, behaving irrationally and suspiciously—that someone being you.’ Not giving Simon a chance to respond, Dunning asked, ‘Where’s Sergeant Zailer?’

‘Off work. Sick.’

‘You mean at home?’

‘Far as I know.’

‘Was she in London with you yesterday evening?’

‘No.’

‘Where was she?’

‘At Ruth Bussey’s house.’ Simon sighed. ‘Look, we don’t have to have a problem here. I’ll tell you what I know, and I’ll tell you what I don’t know but strongly suspect. Same goes for Charlie—Sergeant Zailer. You want to put your murder case to bed, the best way to do that quickly and efficiently is to let us help you.’

Proust stood up, leaning his hands on his knees as he rose. Simon had almost forgotten he was there. ‘If I’m about to lose DC Waterhouse, I need to find out where we’re up to on various things so that I can sort out handover. Can you give us a moment, DC Dunning?’

‘Handover?’ Simon echoed. How long did Proust think he’d be gone?

‘Fine.’ Dunning headed for the door. ‘I’ll be waiting outside.’

Once they were alone, Proust said, ‘DC Dunning has tried several times to reach Sergeant Zailer at home, with no success. If you know where she is, I’d strongly advise you to share that information with him.’ The inspector sounded distant. Tired. For once, Simon wouldn’t have minded a spurt of his customary garrulous sarcasm. No point apologising for yesterday; he wasn’t sorry. The only mistake he’d made was to leave London when he did; he might have saved Gemma Crowther’s life if he’d stayed another hour.

He knew what he’d tell Dunning about Charlie: fuck all. She was in a state, and wanted as few people as possible to know. Proust, at least, wasn’t asking to be told; only that Simon should reveal all to Dunning. Handover. ‘Sir, much as I’d like to be shot of Nancy Beddoes, there’s no need to reassign anything of mine—chances are I’ll be back later today.’

‘There is no chance, DC Waterhouse, that you will return to this building later today, or tomorrow, or the day after.’

Simon regretted his attempt to lighten the atmosphere. ‘Dunning’s trying it on, sir. He’ll change his tune. He knows I’m telling the truth and he knows I can help him.’