“Oh, sir.” The boy seemed no older than fourteen or fifteen. His arm shook in Hugh’s grasp, and he gazed around with unfocused eyes. “Sir, will you help us? There are people trapped under there.”

He shook Hugh’s hand away, scrambled to his feet and ran, slipping and sliding in the mud, to tear at the upturned carriage.

“Wait,” Hugh called. “That won’t work.” He peered through the murk. Where was the coachman? “Ince!”

“Sir.” The voice came from Hugh’s right. The coachman was struggling to restrain a carthorse so that bodies could be loaded on board the wagon. The poor beast, terrified by human screams and the smell of smoke, snorted and stamped.

“Ince,” Hugh shouted. “Throw me a rope.”

“Sir,” the boy piped up, his voice shrill. He still pushed and pulled at the carriage, his efforts hopeless. “If you can only help me lift this wagon a little, there’s a woman and her child caught below.”

“Are they alive?”

“I can’t tell, sir, I can’t hear them anymore.”

“Hold a moment. We can’t lift that weight by ourselves. We need my horse.”

Hugh ran back to Thunder, who shivered and fidgeted nearby. He untied the black stallion and pulled him across to the upturned carriage. Thunder relaxed in his master’s hands, snorting gently.

Ince relinquished the wagon to others and came running, a rope coiled over his shoulder. “My lord,” he panted. “What should we do?”

“Tie one end of your rope to Thunder and lead him on to higher ground. Be quick about it. God knows how many poor souls are trapped underneath.”

Hugh turned and shouted to the boy, his voice cutting through the chaos. “Come away. You won’t lift it by yourself. Let the horse do the job.”

The boy fell back. The coachman led the horse a few steps, but Thunder resisted, terrified of the lights and noise. His eyes swivelled, whites gleaming. He pulled away from Ince and reared, hooves flailing and thrashing, threatening to add Ince to the tally of injured.

“He’s not used to this kind of work, my lord,” gasped the coachman.

“No more are the rest of us.” Hugh took the horse’s reins in his own hands. “Come, now.” He kept his voice low and steady. The horse skipped sideways. “Now then. This is no time to be foolish. Just follow me.”

Thunder, settling to the sound of his master’s voice, took a few steps. The carriage creaked.

“That’s better,” Hugh said.

Thunder responded with a few hesitant steps and then, as nothing dreadful happened, pulled harder. The railway wagon creaked, groaned, and lurched. For a moment, it seemed it would not budge, but at last, with a loud suck and gurgle, the mud released its hold and the wagon flew, upside down, a foot in the air.

The boy darted forward. He put out his hand to a woman who sprawled, spread-eagled in the mud. A little girl lay motionless beside her. The woman bawled and screamed, bellowing language ripe enough to shock the costermongers of London.