Two minutes later, when the heavy oak doors of the private dining salon swung outward, the late-afternoon sun hit David before he could even register the room's furnishings. The reflections off the Canal de la Moselle forced him to squint and shade his eyes as he entered. Once across the threshold, he moved quickly into the shade and turned to examine the sun's illumination of the room. The polished mahogany dining table glowed a deep burgundy, the silver candelabra and the crystal glassware glistened.

"Ah, David," Wilhelm said, "prompt, as expected."

He turned toward the voice to see Wilhelm as a haloed silhouette against the windows. "I am sorry, mein Prinz. I was blinded by the sun and did not see you there."

He chuckled. "It is a fine ploy of hunters." As he moved from the windows toward the table, he added, "Shall we be seated?"

While David waited for him to settle into his chair, Wilhelm's eyes paused briefly at his throat, with a faint, amused smile.

"Your Royal Highness, please accept my sincere apologies for the informality of my attire this evening. I left this morning expecting only a swift day of transit and logistics. Had I known I would be granted the immense honour of your table, I would have packed a wardrobe fit for the court."

"Ah, but David, I must commend you. Most men given such short notice in these times would have appeared at my table looking like a bedraggled courier. Yet you manage to navigate it with the poise of a seasoned diplomat."

David bowed his head in deference, then took his seat. "You are exceptionally kind. A gentleman does what he must to ensure his presentation does not insult the grace of his host. To sit across from you in anything less than my absolute best would be a greater blunder than any tactical error."

Wilhelm let out a short laugh. "Tactical errors can be corrected by artillery, but an insult to good taste is entirely unforgivable –" He paused as a liveried footman approached and poured the Weißburgunder.

When he left, Wilhelm continued, "I spend my days surrounded by generals who are buttoned up so tightly they can barely breathe. If anyone has earned the right to sit at my table in comfort, it is the man who brought me these bottles of nectar."

He raised his glass, peered into it and nodded. "In fact, let us call it the prerogative of the true connoisseur. Here, taste matters far more than starched linen. To your exceptional health, David, and to the magnificent bottles that brought us here."

David felt the tension in his shoulders ease as he raised his glass to meet the Prince's toast, knowing that his social navigation had not only averted a blunder but had also successfully cemented his status as a privileged guest of the Crown Prince.

Their first course arrived, river trout in lemon and butter. Wilhelm watched the plates set down, nodded in approval at the saucing and then turned his attention back to David. "You see, they remember how to cook properly when threatened."

"Yes, this is truly a French rendition – we call this à la Meunière in Bienne."

"You teach me about both wine and food. Perhaps this war is not entirely a waste."

David smiled, sensing more bitterness than humour in Wilhelm's tone. "Small islands of calm are worth cultivating, sir."

"Calm." Wilhelm tasted the word along with the fish. "Tell me, David, when you walk through Bienne, Bern or Zürich and read the newspapers there, do they call this calm?"

David took a careful bite, allowing himself a moment to think. "They call it many things, sir. In Switzerland, one may read communiqués from all sides on the same page – German, French, British, sometimes even Russian. The editors place them side by side and let the readers compare."

"Compare." Wilhelm snorted. "We have no need to compare. We know what is right."

"Then perhaps the comparison is more for the benefit of those outside. They watch what is said and what is done – troop movements, wounded, rationing ... over time, patterns show."

"Patterns." Wilhelm's fork paused midway to his mouth. "And what patterns do they think they see now?"

"That all sides are bleeding. That this summer will be harder than the last. And that Germany is shifting much of its weight north-west." He lifted his glass. "They note that Verdun is still unresolved, but that more trains roll past it to the west."

Wilhelm's jaw tightened. "They think that already?"

"Some do. The railways are hard to hide, sir. Even neutrals must use them. Schedules change. Sidings fill. Civilians are turned away from certain routes. People speak."

He let the subject rest there and turned his attention back to the trout. "But the food is excellent. The chef has done you credit."

"He should," Wilhelm said. "He has not had to stand in mud up to his knees." He ate in silence for a while, then added, almost to himself, "Perhaps when this is over, some vineyards will remain."

"Vineyards have deep roots. They have seen many wars and have outlived more empires than we can count."

"The optimist again," Wilhelm murmured. "My father would like you. He despises pessimists even more than fools."

The second course was a roasted pheasant with mushrooms and a dark, glossy reduction. The Blauburgunder provided superb accompaniment, and Wilhelm relaxed further as the wine harmonised with the food.

"You were not exaggerating," he said, swirling the glass. "About the pairing. The wine tastes different now than in the carriage."

"Food does that. It can either fight the wine or make it show facets one had not noticed."

"And what facets do you notice now?"

David took a measured sip and let it sit. "A little more of the game – the pheasant draws out the savoury notes. The forest floor, the smoke. The fruit stays, but it now shares the stage." He set the glass down. "Like something that has stopped moving and settled into the ground."

Wilhelm gave a short, sharp laugh. "Always back to the soil with you."

"Soil provides sustenance, grows food, supports families, feeds armies." David paused for a moment to consider how to proceed. "But it is not endless; it must be replenished with fertiliser, but the materials for that are being sent to France instead."

"Sent to France?"

"As explosives. The ammonia needed for fertiliser has been diverted to make munitions for the men to fire into France. The crops fail, and those left behind – the women must struggle to wrest food as if from stone."

"Ah, the women." Wilhelm waved his fork vaguely. "From Berlin to Baden, they all write the same. Potatoes, flour, coal, horses. Always something." He took another bite of pheasant, chewed, then added more quietly, "Sometimes I think the only honest reports we receive are in their letters."

David tilted his head. "Honest, because they have nothing to gain by exaggeration."

"Yes, we promised them a short war, quick victories, spoils. What they have is queues, funerals and fields turned with spades." He lifted the glass again. "They do not even bother to curse the French or English now. They curse the clerks."

David nodded. "The officials are present. The enemy is only an idea they have never seen."

Wilhelm grunted. "You sound disturbingly like some of the letters my staff read aloud to me." He took a long drink of the Blauburgunder. "Enough of women for tonight. Speak to me about wine again."

Dessert was a delicate pastry with apricot and a thin glaze, and with it the Yquem returned to the fore. The burnished gold caught the candlelight, and the waiter seemed more careful as he poured.

"You Swiss ..." Wilhelm said, "you stand aside and watch the world beat itself to pieces, and then you measure the fragments."

David sensed no accusation – only weariness. "We stand aside because we are too small to stand in the middle. And because we know that great mechanisms rarely notice what they crush." He gently swirled his wine. "So we try to watch where the gears slip, and where they grind too hard."

"And what do your measurements tell you about this mechanism?"

"That it is running hotter than last year. That there are too many parts under strain. That if nothing changes, something will break – perhaps at the Front, perhaps behind it."

Wilhelm nodded and leaned back. "Where do you think the break will come?"

"The bleeding of both sides here strains many parts. But the main strain is not along the Fronts; it is far behind them. Winemakers unable to get bottles because the war demands glass. Crops suffering for the want of fertiliser. Women turning soil with spades because there are no men or horses." He raised his glass slightly. "But what do I know, sir? I am only a watch salesman and a wine merchant."

"And a dangerous observer." He drained the last of his glass and set it down. "I expect you to bring more information with the rest of the Yquem and the gold watches."

"I shall, sir. And if you wish, more of my great-aunt's wine."

"Yes, of course. I shall sign a new pass for you and send it to Bienne." He chuckled. "See if I can be poetic like you and find some wording to satisfy the guards that it is not nitroglycerine."

David rose with him. "Making it easier for me to bring both the wines and the news."

"And pray that when you next pass through Metz, the trains still run both ways."

He turned toward the door; David followed at a polite distance, filing away not only the words but the tone. The wines had done their work. Now he needed to distil the evening into shape for London – without losing the flavour that made it meaningful.