I know exactly where you’ll be, Craig thought. The National Police Chiefs’ Council convention in Scarborough. It’s no coincidence that she gave me until Thursday to get a result. That’s the day she’s due to give her major speech, and she wanted something to boast about.

Gillard drove over to Claire Mulholland’s home, where he had been promised an early evening meal of scrambled eggs and bacon with the family. Claire had been surprised to hear his news of thallium in the deodorant, and wanted to hear more, even though she was off duty. The detective chief inspector was always a little wary of going to see her because of her boisterous Irish wolfhound, Dexter, whose wildly sprayed saliva could make a mess of any suit. Gillard edged his car onto the cracked pavements outside her Staines home, and made his way between the other vehicles on their paved-over front garden. The moment he rang the front door bell, Dexter hurled himself against the glass door, his stretched front paws giving him a passing resemblance to the wookiee from Star Wars. Claire came and heaved him away from the glass by his collar to allow Gillard to get in. Once the dog had calmed down, Gillard made his way through the sitting room, where husband Baz was watching the TV, and into the kitchen, from which Dexter was barred.

‘Those toiletries that you found at Mrs Roy’s office, where exactly were they?’ he asked.

‘In the drawer of the desk. I don’t think it was locked.’ Claire opened the fridge, got out half a dozen rashers of bacon and set them under the grill.

‘Apart from Philippa Boswell, who has access to that office?’

‘I don’t think it’s terribly secure,’ she said. ‘Mrs Boswell said it was locked after she went home, but both Mrs Roy and Morag Fairburn have keys. It’ll be too late now to do any fingerprints around her desk, drawers and phone, given how many people end up sitting there.’

‘But at the very least a suspect list must be confined to those who work at Empire of Spice’s Slough office, plus family who would not be questioned if they walked in. That may not narrow it down very much except by excluding Jason Waddington. He cannot be the poisoner.’

‘But could he still be the attacker?’ Claire asked as she whisked up eggs and milk.

‘It’s unlikely,’ Gillard responded. ‘Two separate attackers trying to kill her at roughly the same time, or an odd conspiracy. Neither really convinces me.’

‘So what did Delahaye say?’ Claire asked.

Gillard laughed. ‘Well, he finally agrees it must be deliberate and ingenious. As he pointed out, Mrs Roy’s apparent hygiene fetish, having deodorants all over the place, probably saved her life. Well, until she got bashed on the head by a cyclist.’

Monday. 9.15. a.m. Harry Roy was sitting at his desk staring disconsolately at a spreadsheet on his desktop PC. It was his first full day back at work since the murder. There was an enormous backlog but he was finding it difficult to concentrate. His eye was drawn to the small window on which the share price page for Nosh2U was showing. But the price hadn’t moved, and after checking he discovered the shares were suspended from trading. The reason given was ‘pending an announcement’. He kept wondering why, searching the Internet for commentary articles on what this might mean. He had found nothing.