Google presented several sources for definitions. ‘Praemonitus, praemunitus. Knowledge of imminent danger can prepare us to overcome it.’ There was even a link to George W. Bush using the phrase in a speech about Iran. Corporate intelligence, cancer research, travel tips on avoiding pickpockets . . . Not much use.

Cooper clicked through three or four pages of links without success, and was about to give up looking when he saw a different reference. It was a book title, advertised by a seller on ABE, the second-hand book dealers’ site. He clicked on the link and found himself reading a description of the book being offered. A history of the Royal Observer Corps, evidently some branch of the British armed forces. Could that be right?

A fresh search and a few more clicks found a picture of the ROC logo. The figure on the badge was apparently based on an Elizabethan beacon lighter, who used to watch the coast and warn of approaching Spanish ships. And, yes, that was the Corps motto: Forewarned is forearmed.

So there had been a Royal Observer Corps cap badge in Michael Clay’s briefcase, along with the tie and the photograph. Had Clay served in the ROC? And what about the identical badge in Pauline Outram’s jewellery box? Sentimental value, presumably. A former boyfriend? Or had there been women in the ROC? Did it still exist, in fact? Too many questions. But Cooper had an idea there was someone he could ask, who might know those things.

There was obviously more of a local connection to be explored in this case than at first appeared. Patrick Rawson might be Birmingham Irish, but it was only thanks to Pauline Outram that they’d discovered Michael Clay’s origins.

Cooper had almost smiled as Fry had confronted Pauline in that rented house and discovered a fact that might have taken another twenty-four hours for them to turn up.

‘My name is Outram because my mother never got married,’ Pauline had said. ‘Not to Stuart Clay, or anyone else. She died when I was very young.’

‘And you’re from a local family?’ Fry asked, trying to piece together an entirely new angle.

‘Yes.’

‘So how did your mother meet Stuart Clay?’

‘They were neighbours.’

‘What?’

‘Oh, didn’t you know?’ said Pauline. ‘The Clays are from Birchlow originally. But they moved away from the area, and it was only recently I was able to get in touch. Michael didn’t even know of my existence. I was brought up in the name of my adopted parents, and changed it back to Outram when I came of age.’

Remembering it, Cooper really did smile. He felt sure that Fry wasn’t going to like all this.

FRY STUDIED ERIN Lacey with a critical eye. They were sitting in the DI’s office, Mrs Lacey being regarded as the distressed relative of a missing person, even if she had been unnecessarily evasive about her father’s movements earlier in the week.