Tonight, his task was to restore the brasswork on the bridge to its gleaming patina. He’d been understandably preoccupied with his personal plans, but that morning he’d noticed that it had begun to grow dull. So he’d decided to spend the evening with a bundle of rags and a tin of brass polish, determined to nip his slipshod ways in the bud before they became a new habit.

Inevitably, his mind slipped sideways from the repetitious task to the closer concerns of his heart. Tomorrow, they would be heading back down the Rhine, towards the place where all this had begun. Schloss Hochenstein, standing high on a bluff upriver from Bingen, its gothic windows glaring down on the turbulent waters of the Rhine gorge, its grey stone as forbidding as a thundercloud, the legacy of some almost-forgotten medieval robber baron. For years, the Wilhelmina Rosen had motored up and down this stretch of river, his grandfather at the helm never betraying by so much as a sideways glance that the schloss meant anything to him.

Perhaps if it had been situated in a less demanding stretch of water his studied avoidance of so prominent a landmark would have taken on its own significance. In the Rhine gorge, however, skippers had to concentrate every ounce of their attention on the water. It had always been a severe test of the skills of boatmen, with its sharp twists, its rock-studded banks, its unexpected eddies and whirlpools and the very speed of its flow. These days, it was easier because deep channels had been dug and dredged to control the capricious movement of the water. But it still remained a stretch of water where a tourist making a single trip would have stronger memories of the surrounding scenery than a Rhineship skipper who had made the transit a hundred times. And so he had never noticed his grandfather’s stubborn refusal to let his eyes range over the prospect of Schloss Hochenstein.