“Did I?” Shelkin frowned. “I don’t recall.”

“Come off it. You recall everything.” Harding leant across the desk. He sensed he might be able to gain the upper hand after all. “What makes it dangerous ground?”

Shelkin’s lips tightened into a pout. He played for time by flicking ash off his cigarette and taking a long drag on it. Then his expression softened appeasingly. “There’s no danger that I know of. My warning was a clumsy attempt to discourage Miss Foxton from prying further into a puzzle I still had high hopes of solving. She was a journalist. I didn’t want all my painstaking work scooped by her.” He shrugged. “It’s a bitter irony that she subsequently died in circumstances Miss Gashry interpreted as proving there was substance to my warning. But there wasn’t. How could there be?”

“You tell me.”

“It can’t possibly matter to anyone today what Shilling-stone was up to, Mr. Harding. It’s interesting, but inconsequential. Historically speaking, it’s a byway of a byway.”

“How come your ‘painstaking work’ has never got to the bottom of it?”

“Simple lack of evidence. I’ve explored every avenue. They’ve all turned out to be cul-de-sacs.”

“Tell me about some of them.”

“To what purpose?”

“To convince me they really were cul-de-sacs.”

“Good God, this is intolerable.” Shelkin angrily stubbed out his cigarette, the modest effort of which sparked a coughing fit. He braced himself against the edge of the desk as the fit slowly subsided, along with his indignation. There was a long pause as he recovered his breath. Then he started speaking quickly, in a clipped, matter-of-fact tone. “Shillingstone’s exchange of letters with Lord Godolphin, in which he’s given carte blanche to delve where he likes on the Scillies, yields no hint of what he hoped to find there. The second earl was a notoriously incurious man and seems to have granted permission largely because of Shillingstone’s persistence. Shillingstone’s papers were donated after his death to his old college at Oxford, but were destroyed in a clear-out in the nineteenth century. William Borlase’s Cornish Antiquities, published 1754, refers to Shillingstone’s work on the Scillies as ‘unprofitable’ without elaboration. And my extensive explorations of later generations of the Shillingstone family have turned up precisely nothing. Need I say more?”

“Is there any more to be said?”

“Oh, one thing, yes.” Shelkin sighed heavily. “You may as well know. I sense you won’t be satisfied until you do. Miss Foxton came back to see me, on her own, a few days after her visit with Miss Gashry She demanded to know what justification I had for warning her off. I was in no position to give her a satisfactory answer, of course. The post had just arrived that morning and was lying here on my desk, opened but unread. I offered her a cup of coffee in an attempt to lighten the mood. I keep the kettle over there.” He gestured towards the last filing cabinet in the row, on which stood a tray bearing cups and saucers, coffee jar and milk bottle, next to an electric kettle. “While my back was turned, she stole one of the letters. It must have caught her eye while we were talking. And she must have moved very quickly.” He sighed. “Never trust a journalist.”

“How do you know she stole it?”

“Her father returned it to me after her death. He’d found it amongst her possessions. He naturally had no idea how she’d come by it. Borrowed, he assumed. But no. It was stolen. And that morning when she came here has to have been when it happened.”

“Who was the letter from?”

“A man called Norman Buller, whose ancestor the Reverend William Buller was executor of Francis Gashry’s will. Mr. Buller had come across my article in the Huguenot Association journal mentioning Gashry while researching his family tree on the Internet. The Reverend Buller’s brother John was joint MP with Gashry for East Looe-multi-seat constituencies were common in those days-and hence a close political associate. Mr. Buller had a cache of papers left by Gashry at his death and preserved by his executor. He wondered if I wanted to look through them. Obviously, I did. They might conceivably have included a complete version of Gashry’s report on the Shillingstone affair. There would have been two copies, one for Wager’s personal attention, one for the file. Wager’s copy could plausibly have wound up in Gashry’s possession. So, I hastened to Mr. Buller’s door. Miss Foxton had been there before me, as I feared, passing herself off as my assistant. The papers were humdrum stuff: letters from John Buller about constituency management and details of Gashry’s subscriptions to government loans. Hardly anything related to his Admiralty career. There were a great many documents, however, and Mr. Buller didn’t claim to have read all of them. From which followed, of course, the dismal conclusion that he couldn’t be sure Miss Foxton hadn’t removed any during her visit. She’d been left alone with the papers for an hour or more, apparently. He insisted he’d have noticed any attempt on her part to remove some of them, but I wasn’t convinced.”

“If she had taken something, surely it would have been discovered amongst her possessions after her death, like Buller’s letter.”

“My thought exactly. But her father insisted there was nothing else and his distressed condition discouraged me from persisting with my enquiries. I did contact an amateur historian who’d been with Miss Foxton at the time of her accident, but-”

“John Metherell.”

“Yes. You know him?”

“I’ve met him. He’s writing a book about the wreck of the Association.”

“So I believe. Anyway, he couldn’t help me. Miss Foxton’s discussions with him had been limited to the Association story. The friend Miss Foxton had been staying with on St. Mary’s said Mr. Foxton had taken everything of his daughter’s away with him. It was a dead end.”

“You gave up?”

“I had to. Just as you’ll have to give up trying to find the Tozers’ ring. Eventually.” Shelkin lit another cigarette and inhaled cautiously. “When the time comes, you’ll know. Believe me. I speak from experience.”

I often attend evensong at the cathedral, Mr. Harding. I did so on Sunday. And I spoke to the dean afterwards. So, I think you’ll agree I have an unimpeachable alibi for the night of the burglary at Heartsease. Even supposing I need one, which, in the absence of any credible motive, I don’t suppose I do, do you?”

Shelkin’s parting shot had hit home. Standing on the platform at Newark North Gate station waiting for the connecting train to London late that cold afternoon, Harding asked himself what, if anything, he had gained from his trip to Lincoln. Considering he had not really wanted to go in the first place, the answer was dismally little. He did not believe Shelkin had either the Tozers’ ring or the missing pages from the Gashry report. Kerry Foxton might have stolen a complete copy of the report from Norman Buller, but it was much more likely she had not. Besides, as Shelkin had said, the contents of those missing pages could hardly matter now, all of two hundred and seventy years later.

Hayley rang as the train was nearing King’s Cross. And Harding made no effort to conceal his pleasure at hearing from her.

“I’m going to come down on the sleeper, even if there isn’t a berth. Sitting up all night’s no hardship if I get to see you in the morning.”

“I’ll find out what time it gets in.”

“Early would be my guess. You don’t have to meet me at the station.”

“But I want to. So, that’s settled. Learn anything useful in Lincoln?”

“Not really.”

“No fresh leads?”

“None I need to follow. Which is a blessing, really. It means I can stop dashing around the country on Barney’s behalf and start…” He hesitated, unsure how to continue, for the simple reason that he had no clear idea of what was to happen next in his life.