“I need to see a spectacle-maker anyway,” Frederickson said. “My eye, Monsieur, is sometimes made tired by reading.”

“It is age, mon Capitaine, nothing but age.”

That diagnosis was echoed by Jules Joliot who greeted Captain Friedrich in his elegant shop behind the Palace of Chaillot. Joliot wore a tiny gold bee in his lapel as a discreet emblem of his loyalty to the Emperor. “All eyes grow tired with age,” he told Frederickson, “even the Emperor is forced to use reading glasses, so you must not think it any disgrace. And, Capitaine, you will forgive me, but your one eye is forced to do the labour of two so, alas, it will tire more easily. But you have come to the best establishment in Paris!” Monsieur Joliot boasted that his workshops had despatched spyglasses to Moscow, monocles to Madrid, and eyeglasses to captured French officers in London and Edinburgh. Alas, he said, the war’s ending had been bad for business. Combat was hard on fine lenses.

Frederickson asked why a captured officer would send for spectacles from Paris when, surely, it would have been swifter to buy replacement glasses in London. “Not if he wanted fine workmanship,” Joliot said haughtily. “Come!” He led Frederickson past cabinets of fine telescopes and opened a drawer in which he kept some of his rivals’ products. “These are spectacles from London. You perceive the distortion at the edge of the lens?”

“But if an officer loses his spectacles,” Frederickson insisted, “how would you know what to send him as a replacement?”

Joliot proudly showed his visitor a vast chest of shallow tray-like drawers which each held hundreds of delicate plaster discs. Joliot handled the fragile discs with immense care. Each human eye, Joliot said, was subtly different, and great experimentation was needed to find a lens which corrected any one eye’s unique deficiency. Once that peculiar lens was discovered it was copied exactly in plaster, and the casts were kept in these drawers. “This one is an eyeglass for Marshal Ney, this one for the left eye of Admiral Suffren, and here,” Joliot could not resist the boast, “are the Emperor’s reading glasses.” He opened a velvet lined box in which two plaster discs rested. He explained that by using the most delicate gauges and calipers, a skilled workman could grind a lens to the exact same shape as one of the plaster discs. “No other firm is as sophisticated as we, but, alas, with the war’s ending, we are sadly underemployed. We shall soon have to begin making cheap magnifying glasses for the amusement of children and women.”

Frederickson was impressed, but Frederickson had no way of discovering that the Joliot Brothers had never ground a lens in their lives, or that they simply supplied the same Venetian lens that every other spectacle-maker used. The plaster discs, with their promise of scientific accuracy, were nothing but a marvellous device for improving sales.

“Now,” Joliot said, “we must experiment upon your tired eye, Captain. You will take a seat, perhaps?”

Frederiekson had no wish to be experimented on. “I have a friend,” he said, “whose spectacles came from your shop, and I noticed that his lens suited my eye to perfection.”

“His name?”

“Pierre Ducos. Major Pierre Ducos.”

“Let us see.” Joliot seemed somewhat disappointed at not being able to dazzle Frederickson with his array of experimental lenses. Instead he took Frederickson into a private office where the firm’s order book rested on a long table. “Pierre Ducos, you say?”

“Indeed, Monsieur. I last saw him at Bordeaux, but alas, where he is now, I cannot tell.”

“Then let us see if we can help.” Monsieur Joliot adjusted his own spectacles and ran a finger down the pages. He hummed as he scanned the lists, while Frederickson, not daring to hope, yet fearing to lose hope, stared about the room which was foully decorated with large plaster models of dissected human eyes.

The humming suddenly ceased. Frederickson turned to see Monsieur Joliot holding a finger to an entry in the big ledger. “Ducos, you say?” Monsieur Joliot spelled the name, then said it again. “Major Pierre Ducos?”

“Indeed, Monsieur.”

“You must have very bad sight, mon Capitaine, if his lenses suited your eye. I see that we supplied him with his first eyeglasses in ‘09, and that we urgently despatched replacements to Spain in January of ’13. He is a very short-sighted man!”

“Indeed, but most loyal to the Emperor.” Frederickson thus tried to keep Monsieur Joliot’s co-operation.

“I see no address in Bordeaux,” Joliot said, then beamed with pleasure. “Ah! I see a new order arrived only last week!”

Frederickson hardly dared ask the next question for fear of being disappointed. “A new order?”

“For no less than five pairs of spectacles! And three of those pairs are to be made from green glass to diminish the sun’s glare.” Then, suddenly, Joliot shook his head.

“Alas, no. The order is not for Major Ducos at all, but for a friend. The Count Poniatowski. Just like you, Capitaine, the Count has discovered that Major Ducos’s spectacles suit his eyes. It frequently happens that a man discovers that his friend’s eyeglasses suit him, and so he orders a similar pair for himself.”

Or, Frederickson thought, a man did not want to be found, so used another name behind which he could hide. “I would be most grateful, Monsieur, if you would give me the Count Poniatowski’s address. Perhaps he will know where I might find the Major. As I told you, we were close friends, and the war’s ending has left us sadly separated.”

“Of course.” Monsieur Joliot had no scruples about betraying a client’s address, or perhaps his scruples were allayed by the thought that he might lose this customer if he did not comply. “It’s in the Kingdom of Naples.” Joliot scribbled down the Villa Lupighi’s address, then asked whether Captain Friedrich could remember which lens of Ducos’s spectacles had suited his eye.

“The left,” Frederickson said at random, then was forced to pay a precious coin as a deposit on the monocle which Monsieur Joliot promised to frame in tortoiseshell and to have ready in six weeks. “Fine workmanship takes that long, I fear.”

Frederickson bowed his thanks. As he left the shop he discovered that the passion of the hunt had meant that he had not thought of Lucille Castineau for the best part of an hour, though the moment he realized his apparent freedom from that obsession, so it returned with all its old and familiar sadness. Nevertheless the hounds had found a scent, and it was time to summon Sharpe to the long run south.

It was the ignorance that was the worst, Ducos decided, the damned, damned ignorance.

For years he had moved in the privileged world of a trusted imperial officer; he had received secret reports from Paris, he had read captured dispatches, he had known as much as any man about the workings of the Empire and the machinations of its enemies, but now he was in darkness.

Some newspapers came to the Villa Lupighi on the coast north of Naples, but they were old and, as Ducos knew well, unreliable. He read that a great conference would decide Europe’s future, and that it would meet in Vienna. He saw that Wellington, newly made a duke, would be Britain’s Ambassador in Paris, but that was not the news Ducos sought. Ducos wished to learn that a British Rifle officer had been court-martialled. He wanted to be certain that Sharpe was disgraced, for then no one else could be blamed for the disappearance of the Emperor’s gold. Lacking that news, Ducos’s fears grew until the Rifleman had become a nemesis to stalk his waking nightmares.

Ducos armed himself against his worst fears. He had Sergeant Challon clear the undergrowth from the hill on which the decayed Villa Lupighi stood so that, by the time the work was done, the old house seemed to be perched on a mound of scraped earth on which no intruder could hope to hide.