The guards were lined up beside the locomotive when he passed, burly, no-nonsense looking soldiers of the Argyll and Sutherland Highlanders, elegant in their dark kilts and white gaiters, impressive in the steadiness of their Lee-Enfield rifles with fixed bayonets. Behind them was the massive golden bulk of the Dreadnought, the most singular and by far the most powerful engine in the world. Despite the urgency of his mission Drigg slowed, as did all the other passengers, unable calmly to pass the gleaming length of her.

Black driving wheels as tall as his head, drive rods thicker than his legs that emerged from swollen cylinders leaking white plumes of steam from their exhausts. She was a little travel-stained about her lower works but all her outer skin shone with the seamless, imprisoned-sunlight glow of gold, fourteen-karat gold plating, a king’s ransom on a machine this size.

But it wasn’t the gold the soldiers were here to guard, though that was almost reason enough, but the propulsive mechanism hidden within that smooth, unbroken, smoke-stackless shell. An atomic reactor, the government said, and little else, and kept its counsel. And guarded its engine. Any of the states of Germany would give a year’s income for this secret while spies had already been captured who, it was rumored, were in the employ of the King of France. The soldiers sternly eyed the passersby and Drigg hurried on.

The works offices were upstairs in the station building and a lift carried him swiftly to the fourth floor. He was reaching for the door to the executive suite when it opened and a man emerged, a navvy from the look of him, for who else but a railway navvy would wear such knee-high hobnailed boots along with green corduroy trousers? His shirt was heavy canvas and over it he wore a grim but still rainbow waistcoat, while around his pillar-like neck was wrapped an even gaudier handkerchief. He held the door but barred Drigg’s way, looking at him closely with his pale blue eyes which were startlingly clear in the tanned nutbrown of his face.