The allied forces were spread like a net to trap an emperor, but as soon as the Emperor touched the net it was supposed to contract and entangle him. That was the stratagem, but the Emperor was as aware of those allied hopes as any British or Prussian officer and he would be planning to slash the net into two pieces and separately tear them apart. Shape’s urgent ‘duty was to discover whether this was the Emperor’s slashing stroke, or merely a cavalry raid launched deep into the Belgian province.

From the crest of the next hill he saw more French Dragoons. They were half a mile away, but on Sharpe’s side of the river and barring his approach to Charleroi. They saw him and kicked their horses forward so Sharpe turned his tired mare northwards, and spurred her into a gallop. He crossed the road, thumped across a pasture, then dropped into a small valley where a tangle of thorns grew either side of a trickling brook. Sharpe forced his horse through the bushes, then turned east again. He could see a wood far ahead of him. If he could make the shelter of the trees he thought there might be a chance of watching the high road from the wood’s far side.

The French Dragoons, content with having chased the lone horseman away, did not follow him. Sharpe slapped the mare’s neck which was wet with sweat. “Come on, girl! Come on!” She was a six-year-old hunter, docile and strong; one of the horses that Sharpe’s friend Patrick Harper had fetched from Ireland.

It was cooler and very quiet in the wood that was tangled with old huge trees. Nosey trotted close at the mare’s heels. Sharpe went slowly, threading the horse between the ancient trunks and past fallen, moss-covered logs. Long before he reached the edge of the wood he knew this was no mere cavalry raid. He knew because he heard the distinctive, never-forgotten thump and jangle of artillery on the move.