David rose, took the brown bottle from the ice bucket and wiped the condensation from its shoulders with a folded napkin. Then he broke the wax seal, eased the cork free and held it to his nose for a moment, savouring the faint scent of chalk and ripe apple.

"First, the Weißburgunder, sir," he said. "This comes from slopes in Schaffhausen, similar in both latitude and soil to Burgundy's Corton-Charlemagne, and because it lies closer under the summer sun than the vineyards here, the grapes gain more ripeness."

Wilhelm watched with narrowed eyes. "So less need to add sugar."

"Among other benefits." David poured a small measure into the prince's glass, then the same into his own, and set the bottle back into the ice. "You will find this very different from what you know of white wine, Your Imperial Highness."

Wilhelm lifted the glass and peered at the pale gold liquid. "It looks like any other."

"Looks can deceive," David said, settling back into his chair. "It is best to appreciate what our nose tells us first."

Wilhelm brought the bowl to his nose and inhaled cautiously. For a moment, his expression remained guarded. Then one eyebrow twitched upward. "This is very profound – unlike Liebfraumilch."

"Indeed, sir," David replied, allowing himself a faint smile. "Nor is it like a Saar or Mosel Kabinett dressed up with extra sugar."

The prince sniffed again, more deeply this time. "There is much fruit, but it is not simple."

"Exactly. I sense a mix of baked apple, pear and pineapple lightly spiced with cinnamon, and beneath that, something like the smell after rain on a courtyard. Swirling the wine like this allows us to find these and more."

Wilhelm nodded, swirled his wine and brought the glass to his nose again. "Now even deeper."

"Yes, that complexity comes from the chalkiness of the soil. Grown in areas without it, wine does not achieve this quality."

Wilhelm nodded and took a sip, his face remaining neutral for a moment, before it registered surprise. "No sweetness – but not thin." He worked his mouth for a while, then added, "It has weight, like Beerenauslese, but without the sweetness. And the flavours continue."

"That is what we look for in the great dry whites, sir. Structure and length. Sweetness can be pleasant, but it is also the easiest thing to add. True quality shows when there is no sweetness to hide behind."

Wilhelm glanced at the glass again. "Here, when we speak of white wine, we think of Liebfraumilch – soft, slightly sweet, harmless. This is not harmless."

"Indeed, sir. Wines like this are meant to stand beside food of some weight – veal in cream, river fish in butter, even goose. It has the acidity to cut through fat and the body to keep its own character."

The prince took another sip, larger this time, then leaned back. "You said Corton-Charlemagne."

"Yes, this is similar to that – different slopes, different vines, but the same spirit."

He took another sip and savoured for a while, then said, "I see why you poured this before the Yquem."

"Yes, always the drier wines first," David said. "If we began with sweet, everything that followed would taste bare and simple. This way, our palates can climb."

Wilhelm stared at the glass for a moment longer, then gave a small nod. "You have given me something new, David. That is not easily done."

"There is more where this came from, sir." He nodded toward the box. "It would be best to taste my great-aunt's Blauburgunder before the Yquem."

"A red." He curled his lips. "I remember only harsh and bitter ones in Reims. This is why I stuck to Champagne."

David took the bottle from the box, removed the wax seal, and withdrew the cork while Wilhelm got two more glasses. Then, as he poured, he said, "Because of the travel, the sediment was disturbed, and it is likely not yet fully settled. It is best to pour very slowly."

"Sediment?"

"White wines are fermented grape juice, while reds are fermented whole grapes, acquiring their colour and tannin from the skins. Tannin allows the wine to age gracefully for many years, and during this, it slowly crystallises into sediment and sinks to the bottom. When a great red is tasted too young, the tannin gives the harshness and bitterness you would have found."

Wilhelm nodded as David slowly poured and explained, then he said, "You have taught me another new thing, David."

He finished pouring and set the bottle down. "Now, shall we allow this wine to teach us more?"

Both men picked up their glasses and swirled the wine before lifting them to their noses. David's shoulders dropped, and he watched Wilhelm's expression change to one of awe. Then he said, "This is the nature of a great Burgundy as it begins showing maturity."

"Mein Gott!" Wilhelm shook his head. "And this is from only grapes? I smell black cherries and prune plums."

"Yes, only grapes. You might also smell crushed rose petals, black truffles and damp forest floor."

Wilhelm nodded and sniffed again. "And fine leather ... and sweet wood smoke. All this from grapes?"

"Yes, and these aromas will all evolve, slowly growing in magnificence over the years. Shall we taste?"

After Wilhelm had savoured his sip, he said, "The cherry is now a bit tart, and the plum is as a compote."

"Yes, the tartness is showing its youth, but it is now more intriguing than offensive. Younger, this would have been a bit harsh." David took another sip, then continued, "I taste a hint of salted liquorice and dry-cured meat. Wines such as this demand being enjoyed with rich meals."

Wilhelm looked up from savouring another sip. "Meals such as ...?"

David shrugged. "Roasted pheasant, squab, or duck. Grilled venison loin or slow-braised beef short ribs. And tell the chef not to spare the mushrooms and truffles."

"You cause a hunger in me." He nodded toward the ice bucket. "You have shown the Swiss mastery of wine. Shall we see if the French can match it?"

David nodded, lifted the heavy white bottle from the ice bucket and wiped it dry. "Château d'Yquem, 1906, sir."

Wilhelm leaned forward and examined the label. "This is the one you boasted of in Karlsruhe. The one you claimed rivalled my 1893 Eiswein."

"I said it came near it," David corrected. "The 1893 Steinberger still holds its own. But this will allow us to refresh our memories."

He broke the wax seal, eased the cork free with care and inhaled. The room seemed suddenly quieter as he poured a modest measure into Wilhelm's glass, then his own. The colour was much deeper than the Weißburgunder – a burnished gold that clung to the crystal as it swirled.

Wilhelm lifted the glass and sniffed. His eyes widened a fraction. "Das ist ..." He stopped, searching for a word. "Dichter. Denser. Honey and apricot. And something like ..." He frowned faintly. "Like the inside of an old wardrobe."

"Old wood and linen," David said. "Botrytis does that. It concentrates everything – sugar, acid, flavour."

"Botrytis." Wilhelm glanced at him. "The noble rot you spoke of."

"Yes, as Herr Valckenberg explained in Worms, on insufficiently ripened grapes it is spoilage; on fully ripe ones, it is concentration and magical enhancement."

"Ah, Worms. Where we met." He nodded, took a small sip and closed his eyes. For a moment, his expression was oddly unguarded – less Crown Prince and more man. Then he swallowed and let out a slow breath. "Verdammt! You were not exaggerating. It tastes like the Valckenberg cellar. Before everything became mud and bone."

"A happier time, sir," David replied, pouring a modest measure for himself. "Though I recall General Knobelsdorf interrupted us before we could truly appreciate the Trockenbeerenauslese that afternoon. He was quite protective of your time."

Wilhelm let out a sharp, bitter laugh that sounded like a bark. "Protective? No. Konstantin likes to pull the strings. He thinks because he wears the uniform of a Chief of Staff, he owns the Crown Prince." He swirled the amber wine violently. "He elbowed me like a misbehaving schoolboy because I told you we were going to bleed the French white at the Meuse. Well? We bled them. And now we are drowning in our own blood."

David took a measured sip of the Yquem, letting the intense sweetness mask the spike of adrenaline in his chest. He is primed.

"The strategy was flawless, sir," David murmured, adopting the tone of a sympathetic confidant.

Wilhelm shook his head, his hand trembling on the wine glass. "Flawless? Hah! Falkenhayn's plan was to bleed them into surrender. We bleed more than the French, and they continue. My Army is no longer an offensive weapon, David. It is being turned into a shield so Falkenhayn can sleep at night."

"He may have underestimated their strength." David lifted his glass and swirled it, then took a tiny sip and let the richness flood his palate, remaining silent for a long while, before he said, "One never has to exaggerate with wine like this, sir. As sweet as it is, the acidity keeps it alive, so it is not cloying."

"Yes, the wine." Wilhelm took another sip, smaller, more measured. "With the Eiswein, the sweetness stands in front. Here, it seems to come from behind." He gestured vaguely with the glass. "It arrives late and stays longer."

"Exactly." David nodded. "The Eiswein shouts its sweetness. Yquem whispers it into our souls."

Wilhelm smiled despite himself. "You have missed your calling, David. You should have been a poet."

"Watches, wines and words all require precision, sir," David said. "And if they are unwisely used, they can disorient."

Wilhelm's smile faded, and for a moment he stared into the glass, then looked past it at the map again.

"When this is over – whichever way that looks, there will be very little left of such things. The French vineyards, the German vineyards, your aunt's slopes. Shells and boots do not respect vines."

"But roots go deep. They have seen many wars."

Wilhelm grunted. "Optimist." He set the glass down carefully. "And what do your Swiss watchmakers say? When will this madness end?"

"They say only that nothing mechanical can run forever without repair. And that the more complicated the mechanism, the more points at which it can fail." He paused for a moment, watching for a reaction. "An Empire is a more complicated mechanism than a watch."

Wilhelm's eyes narrowed. "Careful, David. That skirts treason."

"Only physics, sir," David said with a shrug. "Wear and stress. Gears under too much load."

The prince looked at him for a long moment, then reached again for his glass. "And which gear fails first, do you think?"

"The one under the greatest strain. And often the one whose teeth have been ignored the longest. The women in Elsass and Baden say the countryside bears more than its share of strain."

Wilhelm gave a short, humourless laugh. "They would. Women always have complaints."

"This time, their complaints align with what I see in my travels. Nearly empty produce markets, yellowed crops in the fields from lack of fertiliser, women turning soil by hand because there are neither men to help nor horses to pull ploughs." He lifted his glass and tilted it in the light. "This wine comes from the soil."

For a long moment, Wilhelm said nothing. Then he took another measured sip of the Yquem and looked away. "You bring much truth in such a small bottle, David."

"Wine does not lie."

"True." He swept a hand past the three open bottles. "And much truth remains there. You will join me for dinner this evening, so we can examine more of it."