Thursday, 8th June 1916

After breakfast, David led Bryce through the upper vineyards to the crest of the ridge, and as they sat on the flat stone beside the switchback path, he pointed down the slopes eastward. "That is Meyerhof, the family estate of Rachel's late husband, Edom."

Bryce nodded as he examined it. "From the vineyards and outbuildings, it is clearly also making wine, and it appears well-maintained."

"Yes, it continues strong, as do Maria's paternal grandparents. In 1905, Edom, Rachel and their three children moved from there to Germany, restored a rundown winery and replanted its vineyards. Their success inspired Bethia to plant a vineyard in Erzingen, thinking if her niece could make wine, so could she."

David turned and pointed westward. "But that's not the reason I brought you up here. This spot gives us a superb overview of the layout of Sonnenhang – its vineyards, the schloss, its outbuildings, the water turbine and cistern, the –"

"Water turbine and cistern?"

"To supply electricity, running water and heating throughout the estate. There's a strong stream tumbling down from the hills, and we installed a turbine to feed massive battery banks. To prevent their overcharging, excess current is automatically diverted to heating coils in huge water tanks."

"Aha, the near-limitless hot water you mentioned."

"Indeed. And also from here, we see the three vineyard tool sheds and Bethia's Erzingen estate – the successive stages of the tunnel."

"So, the returning men use the far one until the extension is complete."

"Yesterday and today, yes." David pointed again. "You can see how the Swiss and German border posts would have a clear view of it, so stealth and timing the guards' movements is essential, both for coming and going. That's the reason we have those men working in the vines around it – the guards become complacent with the movement."

"But the men have Swiss identification. Why not use them at the border? Use their salesman status as the reason to enter?"

"A few do, but too many similar crossings in a short time would cause suspicion. Besides, not all of the men have proper papers. The forged and artificially aged ones that London supplied have become too dangerous to use. We suspect that's why we lost two of the team last month."

"Lost two?"

David winced. "They were investigating the gasworks on the ridge above Pirmasens and missed the planned rendezvous with the rest of the team. They didn't show up at the alternate, nor did they use the default return to Sonnenhang."

Bryce pursed his lips and nodded. "The interrogation procedure you described – remain silent and be emasculated, tell all and still be emasculated."

"Yes, among the things I learned during my last meeting with Wilhelm." He blew a loud breath. "But to present matters – we no longer trust forged papers. And also, among Karl's team were escaped prisoners of war – no papers, not even forged. Beginning with the next mission, they'll use the entrance in the courtyard."

"Aha, the reason you told Gerrard to pitch a tarp cover over the works."

"Partly, yes. But mainly to keep it hidden from anyone who more than casually glances through the gate's grillwork."

"He could cover the grillwork with canvas."

"Yes, even better. Clear thinking, Bryce."

After a long pause, David pointed down the slopes to the schloss and chuckled. "We've breakfasted and walked in the sunshine, so Bethia should now allow us to sort the reports by district, compare them against the newspapers and begin refining the next wave."

Throughout the morning, the remaining agents returned, most using the tunnel, while some crossed at the border. During this, David and Bryce sat in the mess with Karl and Horst, sorting previous reports, identifying common themes and regional differences, and relating these to the variation in propaganda across the country. Interspersed with these, they debriefed new arrivals.

Then, during lunch in the schloss, the four men continued refining the team's next approach, now assisted by insights and sensibilities from Bethia and Rachel.

After lunch, David and Bryce drove back to Bern, and along the way, they drafted a message to R, giving a précis of the reports on troop and equipment moving westward past Verdun, informing him of the tunnel breakthrough, and outlining the findings from the first wave of subversion.

Immediately after arriving at the embassy, they double-encrypted the message and had it sent. With it receipted, David led Bryce along the hall and knocked on Evelyn's open door.

The Ambassador looked up from papers on his desk. "Come in, come in. Have they broken through?"

"Yes, and only a few feet from perfectly centred. Also, all the men have returned safely from the new mission in Germany."

"With useful intelligence?"

"Yes, very. It gives a clearer understanding of the situation and provides a direction for our next approaches. Some of it reinforces what we learnt from Hans, and I've just sent a message informing G."

Evelyn nodded, glanced at the clock, then at his desk. "Give me five minutes to secure all this. We'll discuss details on the drive to the residence – or better, save them for dinner – Henry and the women must also hear."

Not long into the drive, Evelyn said, "The first British have finally arrived at Château d'Oex – nine hundred and fifteen of them, Henry told me. And with many profoundly malnourished and suffering intestinal ailments, Edith has diverted a substantial portion of the bureau's production to aid their medical rehabilitation."

From the back seat, Bryce said, "I'm lost here, sir. Shato dukes, bureau?"

"Ah, I see David hasn't yet told you about the wounded prisoner of war programme. Edith and Maria were instrumental in its conception and in establishing it with the Red Cross. As it took shape, Henry was moved from Military Attaché to oversee it."

"Aha! Thus, David's posting here."

"In a roundabout way, yes."

"And the bureau?"

"The Bern Bread Bureau, established by Edith last year, to supplement the meagre diet of our prisoners in German camps. With our naval blockade making them barely able to feed their own people, let alone prisoners of war, they had sunk to near-starvation levels. Using Swiss bakeries and British expatriates living here, volunteers pack, label, and ship thousands of high-nutrition loaves into Germany every week under strict neutral diplomatic immunity."

"What? Feeding the Germans? Why?"

"No, not the Germans. The Red Cross controls the distribution, ensuring everything goes directly to British prisoners. In the bread packages are often chocolate, tinned fish, tobacco, and whatever else is donated or purchased with donations. The Germans allow this because it eases their obligation to feed."

Bryce nodded. "And the shato dukes you mentioned?"

"Château d'Oex is a mountain resort south of here, with hotels and restaurants left empty by the collapse of tourism. Other similar resorts now accommodate the French, Belgian and German disabled prisoners, and the countries share the expense of their accommodation. This not only eases the prisoners' plight, but it also prevents the ruin of the resorts."

"Brilliant!"

"Indeed. Edith is given credit for its conception, but she says the initial idea was Maria's"