Simon ignored him. ‘Another suspect for Angela, initially, was the obvious: husband Russell McCabe. Her death meant the debt on their house being paid off in full by Zurich Insurance – they had a £485,000 interest-only mortgage on it. At the same time, they had nearly two million quid in various savings accounts and investment portfolios, and owned outright a six-bedroom holiday home in Burnham Market in Norfolk. So, did Russell McCabe murder his wife to get his mortgage paid off? We think not, because he was teaching kung fu classes all afternoon. Also, one of the kung fu pupils claims she looked out of the window at one point and saw Angela with someone else in the kitchen of the house. We think that someone else must have been Billy. As far as Russell McCabe knew, or as far as he’s told us, his wife wasn’t expecting any visitors that afternoon. And that’s our one and only sighting of Billy, folks – by a witness who happened to glance out of a window and see someone about 80 feet away, for a few seconds. We got nothing more from that sighting than “a person”, and even that was qualified by “not sure, might have imagined it”.’

‘If you’re done, I’ll do Josh Norbury,’ said James Wing.

Simon nodded and returned to his chair. He wanted it to be Gisela Bloor but he didn’t believe it was, not deep down.

‘Joshua Norbury, forty-five, single,’ said Wing. ‘Gay. Had a flat in the old Corn Exchange building in Spilling. He worked as a manager at a chemical waste plant between Rawndesley and Combingham. Murdered – shot to the back of the head – on 17 December 2014. Like Rhian and Angela, killed in his kitchen. Josh was found by his cleaner, Andras Nagy, two days after his death. There were mugs on the kitchen counter, but they were clean. Empty. Billy was getting impatient, perhaps, on his fourth killing expedition – couldn’t be bothered to do the cup-of-tea-and-friendly-chat part of his routine, so shot Norbury before the first drink was made.’ Wing rolled his eyes. ‘I mean, you can see his point. Why waste time socialising with someone who’ll be dead within the next half-hour?’

In this instance, thought Simon, the eye-roll was at odds with the sense of what Wing was saying. Why hadn’t someone close to him had a word, tried to make him quit the habit? Wing had mentioned a ‘partner’.

‘Josh Norbury was well liked, lots of friends, nothing dodgy or dangerous in his personal or professional life. No one saw or heard anything – no leads, nothing to go on apart from a little white book with a line from a poem: “And a shadow seemed drawn o’er the sun’s golden track”. Ella Wheeler-Wilcox.’