‘I see. Well, what about me? Shouldn’t you ask me for my alibis for all the dates of the murders? And – oh – do you want some DNA from me? Liam said someone rang up about DNA.’ Isobel stuck out her tongue, then put it away again, as if realising she must look odd, sitting there with it sticking out.

‘I don’t do that part,’ said Sellers. ‘I don’t have a kit on me. But if you and your brother could follow up on the phone call you received, I’d appreciate it. We need to rule you out on the DNA front. And yes, I’d like to ask you about your whereabouts on the dates in question, if that’s okay? Again – only a formality.’

Sellers didn’t fancy Isobel Sturridge at all. If she made a pass at him, he’d give her the knockback. Wasn’t often he felt that way. He did a quick analysis of his aberrant response to her and decided it was her teeth that were the problem. There was a noticeable vertical groove at the centre of each of her front teeth, creating a disconcerting two-halves effect.

‘I was at work for all five,’ Isobel said once Sellers had told her the dates. ‘I work nine thirty to five thirty, Monday to Friday.’

‘Where’s work, then?’ he asked her.

‘The famous Rudolphy’s.’ Isobel was unable to keep the pride out of her voice.

Whatever Rudolphy’s was, its fame hadn’t spread as far as Sellers. Typical Silsford resident, he thought, imagining that everything that happens in Silsford is of inherent interest to the world. Two elderly Silsfordians had turned up at the nick last week – Spilling nick – to complain that the police in Silsford weren’t concerned enough about the dreadful wind-tunnel effect created by the new Waitrose on Bicknacre Road. What did Spilling Police intend to do about their negligent colleagues in the neighbouring town? they demanded to know. Answer: nothing.

‘It’s a labour of love more than a job,’ said Isobel. She couldn’t have sounded more self-satisfied. ‘I mean, the money’s negligible. People are always saying how much they envy me, when they’re earning three times my salary!’

Sellers heard the silent addition loud and clear: And yet, we all know I’m in the better situation.

‘So – aren’t you lucky?’ She laughed.

‘What do you mean?’

‘My alibi is Rudolphy’s! Which means you’ve got an excuse to go there now, to check it – and emerge several hours later and several hundred pounds poorer!’

‘I’ll be the one in need of an alibi if I spend several hundred pounds without my wife’s permission.’