The Germans were still ahead of Sharpe. They rode through a small village where Leroux, mysteriously, had turned left. They followed his northward course, the horses plunging a shallow bank into a stream, scattering the water silver bright in the dawn, then onto fields of the far bank. There were hills ahead, shallow hills, and Sharpe wondered if Leroux was hoping for a hiding place. It seemed a forlorn hope.

Then Lossow was shouting, holding a hand up and signalling a stop, the troop pulled left, slowed, and Sharpe caught them up and his protest at abandoning the pursuit died in his throat. Their horses slowed to a walk, stopped. Leroux was safe.

Leroux would reach Paris, the notebook would be decoded, and the Frenchman would win. If they had been given another two miles they might have caught him, but not now.

Leroux was trotting his horse along the face of a shallow hill that sloped up from the wide valley. Lined on the slope was the French rearguard, a thousand cavalrymen, and Lossow spat in disgust. “We can’t do anything.” He sounded apologetic as if he thought Sharpe might truly expect him to charge a thousand enemy with just a hundred and fifty men. He shrugged at Sharpe. “I’m sorry, my friend.”

Sharpe was watching Leroux. “What’s he doing?”

The Frenchman was not joining his cavalry. He trotted along the face of the ranks and Sharpe could see that he raised his sword in salute to the French squadron commanders. Leroux was still going north, past the cavalry, and Sharpe urged his horse into a trot so he could follow the Frenchman. Sharpe led Lossow’s troop north, a half mile to the west of the French line and watched as Leroux went on riding, past his cavalry, and dropped into a valley at the end of the hill. Leroux was now in dead ground, invisible to them, and Sharpe pushed his tired horse into a canter.

There was a hill ahead of them that would overlook the dead ground, and they rode up its slope, the dew sparkling where the hooves hammered the turf, and then it was Sharpe’s turn to hold up his hand, to slow, and to curse. He had half hoped that Leroux was planning to ride on, to go eastwards again with his own cavalry behind him, but Leroux had reached true safety. In the small valley were French infantry. Three Battalions in square and, some way behind them, another two Battalions who guarded the rear of the hill where the French cavalry barred the road east.

Leroux was walking his horse towards the Battalions in square. Sharpe swore again, pushed his sword into its scabbard, and slumped in his saddle.

Hogan leaned on his pommel. “That’s that.”

One of the French squares opened its ranks, Leroux walked his horse inside, and for all Sharpe could have done Leroux might as well be in Paris already.

Patrick Harper flexed his borrowed sabre and shook his head. “I was just beginning to look forward to a cavalry charge.”

“Not today.” Hogan stretched his arms, yawned.

Further eastwards, perhaps three miles away, the road was filled with retreating troops. Going east to safety. Leroux had reached the rearguard, was safe, and would soon be escorted by this infantry to the rest of the French army. Lossow had just a hundred and fifty men. The French rearguard was at least two and a half thousand men, infantry and cavalry, and Sharpe’s last hope vanished like the mist that faded from the landscape.

It promised to be another beautiful day. The meadows of the gentle hills were lush with pasture, lavish with wild flowers, and the first warmth of the climbing sun was on Sharpe’s face. He hated to give up this pursuit, yet what else was there to do? They could ride back to Alba de Tormes, sit by the river’s edge, and drink harsh red wine till all the disappointment was drowned in the vintage of last year’s comet. There would be other days to fight, other enemies, and Curtis’ men were not the only brave people who sent messages to England. There was hope, and if the hope was not bright then there was always wine in Alba de Tormes.

It was pointless, of course, to deal in what might have been, yet Sharpe cursed because they had not left the battlefield an hour earlier. He imagined what he could do if he had just a single battery of nine-pounder guns. He could open those squares with shot after shot, and if he had just two good British Battalions he could finish them off! Hogan must have thought the same for he looked gloomily at the three French squares. “We’ll have no guns or infantry till this afternoon. At the earliest!”

“They’ll be long gone by then, sir.”

“Aye.”

This rearguard would stay just long enough to hold up the cavalry pursuit while the rest of Marmont’s army stole a march on the British. Without guns or infantry the squares could not be broken. Leroux was safe.

Lossow’s men rested their horses. They were north of the enemy now, on a hillside that gave them a wide view of the countryside. The enemy cavalry were on another hill a half mile to the south, the infantry closer, in the small hidden valley, while to Sharpe’s right stretched the wide valley where the two roads met from the river. The furthest road was the one Leroux had led them on, from Alba de Tormes, and where it passed through the small village it was met by the closest road that came from the fords across the river. The enemy dominated both roads, blocking the pursuit. Leroux was safe.

There was movement on the Alba de Tormes road. British Light Dragoons, three hundred sabres, trotted towards the French, saw them, and stopped. The horses bent their necks and cropped at the grass. They formed a single line, facing the French cavalry, and Sharpe imagined their officers squinting through the rising sun at the outnumbering enemy.

Then, from the north west, from the fords, came more cavalry. Four hundred and fifty men walked their horses into the valley behind the British, and the newcomers looked strange. They wore red jackets, like infantry jackets, and on their heads they wore old fashioned black bicorne hats held on by brass-plated straps. It was like seeing a regiment of infantry Colonels. Each man was armed with the long, straight sword like that at Sharpe’s side. They were Heavy Cavalry, the Heavy Dragoons of the King’s German Legion. They stopped behind the British Light Dragoons, slightly to their left, and Hogan looked from them to the enemy and shook his head. “They can’t do a thing.”

He was right. Cavalry cannot break a well-formed infantry square. It was a rule of war, proved time and again, that as long as the infantry were solidly ranked, their muskets tipped with bayonets, horses will not charge home. Sharpe had stood in squares and watched the cavalry charge, seen the sabres raised and the mouths open, and then the muskets had fired, the horses fell, and the surviving cavalry sheered away down the sides of the square, were blasted by the muskets. The squares could not be broken. Sharpe had seen them broken, but never when they were well formed. He had seen a Battalion attacked as they formed square, seen the enemy penetrate the unclosed gap and slaughter the ranks from the inside, but it would never have happened if the gap had been closed. He had seen a square break itself, when the men panicked and ran, but that was the fault of the infantry themselves. The South Essex had broken once, three years before at Valdelacasa, and then it had been because the survivors of another square had run to them, clawed at the tight ranks, and the French cavalry had ridden in with the fugitives. Yet these French squares, below him, would not break. Each was of four ranks, the front rank kneeling, and each was solid, calm, and ringed with bayonets. Leroux was safe.

Leroux was safe because he had taken shelter with the infantry. The enemy cavalry, facing west on the hillside, were vulnerable to a British pursuit. Their safety lay in their greater numbers, yet Wellington’s men had the greater morale. Sharpe heard the far-away sound of a trumpet, he looked right, and he saw the British Light Dragoons begin their charge. Three hundred men against a thousand, an uphill charge, and Captain Lossow whooped at them with glee.