While David waited, he analysed the transportation efficiency he had seen in the past few minutes. So different from what the men report. What Hans reported. But of course, an entirely different class of travel. Everything military has priority. Everyone and everything else waits for space.

He moved the Passierschein from his inside breast pocket to the outside one, folded so the red seal showed. What more might this document allow me to do? Would anything else be safe? Must ask R ...

The hissing and squeal of brakes interrupted his thoughts, and he turned his head to watch the train pull slowly along the platform. Coupled behind the drab grey locomotive and windowless mail car was a long, elegant carriage, its glossy green paint accented by golden pinstriping. It stopped directly in front of him, a large Baden crest painted in the middle, flanked by II and I.

Unable to determine their meaning, he looked further along the train at the short, boxy, dull maroon cars with tall, narrow windows. Then, while passengers disembarked, noise and motion to the left caught his attention, and he watched the decoupled locomotive steam forward. When it stopped and reversed, he realised: A true shuttle. The engine simply changes ends.

The belching black smoke marked its passing on the other side of the now-emptying train, and he examined his coach. Riding on two sets of sprung dual-axle trucks. A comfortable ride, like on the Canadian trains. Then he scanned along to the drab cars behind it. Like the ones I rode on my way from Ypres. Axles bolted directly to the frames. What a noisy, bone-rattling ride that was.

Soldiers in rumpled and dirty uniforms were still filing out from the cars, while ranks of fresher-looking soldiers waited. When the last of the passengers had left the sleek Abteilwagen, a platform guard signalled those sitting with him on the upholstered benches.

David watched the other men, then walked behind them toward the official, taking out his Passierschein and Fahrkarte as he approached. When he showed them, he was directed to the right. Painted in bright golden yellow beside the entrance was a Roman I. Aha, a two-class car. And only seven men ahead of me.

He followed them aboard and along the carpeted side corridor past frosted windows and open sliding doors. Four entered the first compartment, the other three, the second, and he continued to the third. As he settled into the plush, deeply cushioned seat and leaned his head back against the crisp white linen cloth, he thought: Such grand luxury for a half-hour trip. But short enough that the troops won't be rattled silly before arrival.

He felt the car shake, signalling the locomotive had recoupled, and a glance at his watch showed 12:13. With such a short run. Easy to operate on time. A pipeline feeding troops from central Germany to the Front.

A minute later, a heavy-set man entered the compartment, clutching a small wooden box, and greeted, "Guten Tag, mein Herr. Verzeihen Sie das Eindringen ... Good day, sir. Forgive the intrusion ... but on the platform, I saw the seal of His Imperial Highness and hesitated. But now, with little else, I prayed I might find a moment of civilised consideration."

Intrigued by the unexpected boldness, David maintained a polite but guarded tone. "Guten Tag. Bitte, nehmen Sie Platz ... Good day. Please, take a seat. It seems you are travelling with something precious?"

The man sighed and set the box carefully onto the navy cushion beside him. "Eine Last für unser ganzes Tal, mein Herr ... A burden for our entire valley, sir. My name is Albert Bleichert. I manage the cooperative of wine producers at Rappoltsweiler – though in our hearts, we still call it Ribeauvillé."

David inclined his head slightly, noting the subtle French pronunciation. "Der Krieg schont niemanden ... The war spares no one."

Bleichert rubbed his temples and looked down at his box. "Das Kriegsamt in Berlin verlangt ... The War Office in Berlin demands that our cooperative deliver ten thousand litres of Grand Cru to frontline staff, yet they have blocked our access to our bottle suppliers. The wines remain in foudres, slowly diminishing. It will destroy the wine and ruin our people."

"The blockade cuts both ways, Herr Bleichert," David said, keeping his voice low and steady. "The German glassworks are entirely bound to the gas-mask contracts. They will not spare a single furnace for wine bottles, particularly not for Elsass."

"A gas mask protects a soldier for an hour, mein Herr," Bleichert whispered, leaning in so his coat brushed the wooden box. "But our vines have sustained these hills for hundreds of years. Now, the railway inspectors in Straßburg are threatening to seize my entire shipment of bottles from Switzerland, claiming they are war contraband."

The train gave a sudden, sharp lurch as the locomotive cleared the outer switches of the Offenburg yard, the rhythmic clack-clack of the rails signalling their departure toward the Appenweier junction

"Glass is a precious commodity, Herr Bleichert, and not only for gas masks. Field hospitals require countless sterile glass ampoules for morphine and anti-tetanus serums. Trench periscopes, binoculars for the officers, artillery rangefinders and so on, need a continuing supply."

Bleichert unlatched the brass hooks of the box, revealing three slender green bottles. "Look at these – true Riesling from Clos du Zahnacker, not a weak, insipid one from this side of the Rhein. The military governor in Straßburg wants these for his personal cellar. If I can get this box to his desk, he will sign the transport clearances for our shipments."

David leaned back, his eyes narrowing slightly as he looked at the portly Alsatian, trying to make sense of his story. "You have chosen a remarkably circuitous path, Herr Bleichert. The route from Rappoltsweiler to Straßburg is direct. Yet I find you crossing the Rhine east into Baden, then taking the Offenburg shuttle back across."

He raised his voice a bit to be heard above screaming wheels as the train cleared the Appenweier junction and turned toward the Rhein. "I find your story curious, and I am certain that the Feldgendarmerie would find it even more so."

Bleichert's face paled, but he nodded quickly, leaning forward to close the distance between them. "It is a madness, mein Herr, I grant you." He checked the corridor door once more. "But the direct rails through Alsace are entirely paralysed. Just south of Schlettstadt—Sélestat, as our growers call it – the main line was completely severed two nights ago. French sympathisers blasted the culvert near Saint-Hippolyte."

David nodded, wondering whether it was Marcel's work. "A clean break?"

"Total chaos," Bleichert nodded. "The military command has frozen all civilian and commercial rolling stock between Colmar and Straßburg to prioritise the repair trains. My only hope of reaching the military governor before his deadline was to take the train from Colmar to Breisach and Freiburg, then another north to Offenburg, and catch this shuttle back into Straßburg. The war forces us all to take strange roads."

David assessed the man's desperation and nodded. "The culvert at Schlettstadt. If the line is cut, then the entire logistics chain for the southern flank is currently in chaos."

"Precisely so," Bleichert nudged the wooden box a couple of inches closer to David's boots. "Which means the inspectors at the Kehl Bridge will be out of their minds with panic today. They will dismantle every third-class carriage in search of French agents. But this car – this Abteilwagen – and anyone sitting under the shadow of your royal red wax seal will pass over the river like ghosts. I ask you again, mein Herr ... help me get this Clos du Zahnacker to the governor, and the cooperative's network in Straßburg is entirely at your disposal."

David looked down at the box. "Because of my love of wine, I will help you, Herr Bleichert. But the reward is meaningless to me at the moment – I continue onward to Metz by secure rail. Perhaps later."

Bleichert let out a long, shuddering breath, the tension leaving his shoulders so suddenly he seemed to shrink into his plush navy coat. He looked at David with a mixture of profound relief and a new, quiet awe. "You are a gentleman of rare character, mein Herr. To risk the scrutiny of the border guards purely out of respect for wine, the families of the Winzergenossenschaft will owe you a debt that outlasts this wretched war."

He rose slightly and, with a foot, nudged the wooden box beneath David's plush velvet bench, ensuring the dark green fringe hid it. Settling again in his seat, he wiped his palms on his trousers and leaned back. "If the reward is meaningless to you today, then let it stand as a promise for the peace."

Bleichert paused and checked the corridor windows as the train's whistle shrieked in the distance. "But do not underestimate the ears of our valley, sir. You say you travel by secure rail to Metz. If you ever find your way choked by troop deployments or locked down by the secret police near the border, you need only whisper the name Zahnacker to any station master along the Alsatian line. We have deep roots in these tracks, and we do not forget a protector."

Before David could answer, the heavy steel wheels beneath them began to scream. The train decelerated rapidly, shifting both men in their seats. Outside the north window, the sunlit orchards had been replaced by towering grey concrete walls, barbed wire entanglements, and the iron-truss framework of the Kehl Bridge checkpoint. Through the frosted glass door of the Abteilwagen, the heavy, rhythmic thud of boots echoed down the corridor as the imperial border patrol boarded the carriage.