De Richleau laughed. “By no means, Mademoiselle. On a May morning London can be as charming as any place in the world. We will take a walk down Bond Street one day, you and I!”

“Do you know the King of England and the Prince of Wales?”

“I have the honour to be known to His Majesty, also to the Prince.”

“Tell me about them, please.” She looked up at him with large grave eyes. He began to talk to her of Windsor and Balmoral — then Ascot and Goodwood — the yachting week at Cowes, days in the Leicestershire country, hunting with the Pytchley, summer nights on the gentle river that flows by Maidenhead — of the spires and courts of Oxford, and the beauty of the English country lanes in autumn, of all the many things he had come to love in the chosen country of his exile; and in the telling, for an hour, forgot the peril that beset them in the land of snows.

The shadows lengthened, the red ball of the sun dropped behind the trees, the bitter cold of the Siberian night chilled them once more.

Rex returned safely, a little less than an hour after dusk. He would say nothing of his excursion, but seemed strangely elated. They had their frugal meal, Simon’s wound was dressed, and the miserable Rakov exercised; then they turned in for the night — perhaps their last night in shelter and security for many days.

In the morning Rex was up with the first streak of dawn, and systematically began to wrench and break the only pieces of rusted machinery that were not obviously solid; even the Duke, knowing that they were to move that night, and in a more settled frame of mind, lent him a hand. The furnace had been gutted long ago, and the slabs of stone prized up from the floor; every inch of the walls had been tapped for a hollow note, but each sheet of metal gave out the same dead sound. They worked without ceasing, except for a brief snack at midday, until four in the afternoon, and then at last Rex confessed himself defeated.

“It’s no good,” he declared in disgust. “Somebody’s beat us to it, maybe years ago. Perhaps he’s dead and buried with the stones still on him, but they’re not here. If only the old bum had told me what place he really did put ’em before he died on me.... Sorry, Marie Lou,” he added, hastily. “I forgot the prince was your father!”

“No matter, Monsieur,” she smiled. “We can only think of people as we knew them; to me, the prince was nothing but a wicked old man — he was always malicious, often drunk and cruel, and I used to dread his visits here.”

De Richleau glanced through the window. “In an hour,” he said, “it will be dark; we should lose no time, but make immediately for Rakov’s, that we may drive all night and put many miles between us and Romanovsk.