On Monday morning, after a restful night and a large breakfast at Hôtel de la Cloche, David and Maria took their luggage down to the lobby and left it with the bell captain. Then, as they joined Michael and Mary in the lounge, Maria said, "Our train isn't until this afternoon. Can we visit the museum? The brochure calls it the oldest in all of France – and still one of the finest."

Michael looked up from his seat. "Possibly another time. We're waiting for a car from Domaine Ducroix. We always visit on our Burgundy trips, and since the war has interrupted so many routines the past two years, I couldn't forgo this opportunity."

"Oh, what is it?"

"A wine estate south of here. For generations, the family has produced some of the finest Burgundies, and I thought our visit would also be an opportunity to introduce David to the subtleties that contribute to making great wine here."

"Excellent! I need this for my next meeting with the prince – to have him continue regarding me as a wine expert." David grinned and chuckled. "Hah! Expert? Hardly. I'm a neophyte who has landed among oenophiles and winemakers."

"Ah, but you are a neophyte with a naturally superb palate, a great analytical mind, and an amazing memory. You need only the breadth of experience to -" Michael paused and rose from his chair, calling to the man approaching, "Louis! I had expected you would send a driver, not come yourself."

"This is an unbusy time, and there is no need for me in the vineyards or the cellar." He shrugged. "So, why not? Besides, it means I see you again sooner."

After introductions, Louis led them outside to his car, and as they rode southward out of Dijon, Michael explained David's need to display a depth of knowledge. Then Louis asked, "May I ask who he needs to impress?"

"Yes, you may ask." Michael laughed. "But I cannot tell you – except to say it is for our war effort and yours."

Louis nodded. "I love the intrigue of espionage, and I respect its need for secrecy. We shall say no more about this." Then he pointed through the windscreen. "There, beyond the last houses, the vineyards begin."

Louis explained the geography as he drove them through Marsannay and into the Côtes de Nuits, then after a quarter-hour or so, he pulled the car to a stop at the side of the road. "Here is a fine example of what I've been saying – how the soil influences the quality of the wine. Across the road, the soil is from an ancient seabed and, later, from the flood plains of the Saône River. It is too rich to make good wine. But on this side, the land begins to rise from the ancient seashore and riverbank, and the soil changes to a mix of marl, gravel and sand, well-drained and suitable for vines."

He turned and pointed. "Wheat and sugar beets on that side of the road, vineyards on this. Now, you see where the land rises more steeply. From here to that point, we grow what are called Village Wines. In the lower slopes, with the beginning of the limestone mixture, we grow Premiers Crus, and higher up in selected plots, we grow the finest, the Grands Crus."

David nodded. "So, it's like my great aunt's vineyards; the best wines come from well-drained slopes and calcareous soils."

"Exactly. The soil and the vineyard orientation determine the quality, and we call this combination terroir. In this area of the Côtes, the limestone, marl, gravel and sand mixture is ideal for the pinot noir grape. South of here, near the city of Beaune and beyond, there is a higher content of limestone, making it ideal for the chardonnay grape."

Louis continued explaining the region and pointing out examples as they drove south. Then, in the village of Morey-St-Denis, as he steered the car into the courtyard of Domaine Ducroix, Maria exclaimed, "Oh, my! What an elegant house."

"Thank you. When my grandfather had it built, he had visions of a very large family."

"And were his visions fulfilled?"

"He made the beginning, but he did not return from the War of 1870 to see how his sons and grandsons succeeded. The house is now too small for us all." He stopped the car at the side of the courtyard. "We'll begin in the cellar with the 1915 – they are of a quality similar to our 1911."

Much as we found with the Sonnenhang vintage." David said as he assisted Mary from the car. "It just occurred to me – the latitude and climate here are almost identical to those in Schaffhausen, and the soils and slopes are similar."

"Indeed. But quality also depends on the viticulture – how the vines are pruned, trained and tended." Louis shrugged. "Great wine cannot be made from poor grapes. Then there's the viniculture – when and how the grapes are picked, selected and fermented." He shrugged again and smiled. "Poor wine can be made from great grapes."

He opened a broad oaken door, turned some light switches and led the way down the stone steps into the cellar. "All but the 1914 Grands Crus are now in bottle, so these are mostly 1915. We harvest, ferment and mature separately the wines from twenty-one vineyards spread across three communes. We'll begin our tasting with a few of the village wines and work our way up."

While they tasted and spat the third wine, Maria sidled up to her grandfather and whispered, "Good, but not as complex as Tante Bethia's."

He whispered back, "These are from the lesser vineyards - the ones with less limestone in the soil. Wait until we reach the wines from the slopes."

Louis tapped the bung back into the barrel; then he pointed along the aisle. "These are all much the same quality, so we'll move along now to the Premiers, beginning with the Morey-St-Denis Les Genavrières."

After tasting that, then the Monts Luisants and Les Chaffots, Maria said to Louis, "These three show a family resemblance, but each has an individual character. I see why you keep these separate. My aunt ferments and ages hers all together – well, the pinot noir and the chardonnay separately."

"I've brought you examples of her wines, Louis." Michael shrugged. "Barrel samples from last year's harvest and some of her 1911. I think you'll find them more than agreeable."

Louis pursed his lips and nodded. "We can look at them during our luncheon. But now, let's move on to the Clos de la Roche, the Musigny and the Clos de Bèze, your three favourite Grands Crus."

Louis led them to the back corner of the cellar, worked the cork bung free from a barrel, dipped the pipette in and drew up a column of wine. Then, as he dropped some into each of their glasses, he said, "This is our Clos de la Roche."

"Oh, my!" David said. "The first waft of aroma is reminiscent of Tante Bethia's ageing cellar."

"It is, isn't it?" Maria nodded; then she swirled her glass and lifted it to her nose. "Similar concentration and complexity."

Louis huffed. "Quality such as this is not possible outside Burgundy, nor even outside the Côtes de Nuits."

Mary looked up from her glass. "I thought so too, Louis. I believed it until we tasted my sister's wines. During a dinner in January, we compared your 1911 Clos de Bèze to her 1911, and we couldn't decide which we preferred."

Louis shrugged. "Travel affects the quality, as does poor cellaring. Wines as nuanced as red Burgundy show at their best close to where they are produced."

"'I've found your wines travel well, and our cellar is perfectly stable in temperature and humidity." Michael tilted his head. "A challenge, Louis. If you wish, we can compare your 1911 Clos de Bèze to her 1911 wine." Then he paused and smiled. "Yours directly from the cellar; hers possibly disadvantaged by travel and questionable storage."