They are near the bottom of the slope now, getting into the boggy ground of the river’s flood plain. The mud sucks at their boots. There are pools of brown water where the river’s burst its banks. Around him Thomas can only hear the din of men beginning to run in armour.

And that is when he sees it.

And this time he is sure.

It is waved, like a signal. It rises briefly in the extreme left-hand end of the wall. Riven’s flag.

Thomas stumbles, trips, nearly falls. But he feels as if he is floating, being held up by some unknown force. He feels invincible. The bog beneath him firms and he surges forward.

‘Come on then!’ he roars. ‘Let’s go!’

He elbows his way to the front of the archers, splashing through the mud. He cuts across the line and men follow him, bunching up on the left.

‘Thomas!’ Geoffrey calls. ‘Slow down! Let the billmen take the brunt!’

They are six hundred paces from the enemy line now, six hundred paces from those guns, but Thomas runs on into them, his eyes fixed on that flag. He can hear the enemy roaring at them. At him. He keeps running.

Five hundred paces.

The line is stretching to the left, hollowing out in the middle. Thomas is still ahead, mud caked up to his thighs, leading them towards the King’s right flank. Whatever plans Fauconberg had for his attack they are of no use now. Everyone is pouring after Thomas.

Four hundred paces.

And then the first gun goes off: a spike of grey smoke that stabs across the ditch towards them. It is followed instantly by a clap of thunder. The boulder cuts through the air behind him, throbbing through the space the archers have just left. It drills into the ranks of the men-at-arms who’ve moved up to take their place. The noise is shattering. Thomas glances back to see a man in mid-air, his feet above his shoulders, his head gone.

Behind him an alleyway has appeared in the ranks, paved with the dead and the dying, men skilled in the tilting yard, men who’d trained all their lives with lance and sword and hammer, men who can control a horse with their knees and heels, men now bowled over and left on the ground like butchers’ spoil.

Another gun. Then another. The sound splits the sky. With each one a new hole opens up between the ranks. Smoke drifts across the meadow and the bitter tang of saltpetre fills the air. Thomas can smell it above his own sweat and the blood and the lush earth beneath his feet.