After he lost his parents, Valens had tried to fortify himself with the principles of Epicurus. If suffering overwhelmed the pleasure of life, it was logical and right to end the misery of existence. But the philosophy had not taken deep root in Valens’s soul, and he had come to acknowledge that self-pity was not the same as true pain. There was an irony in looking back. Then he had wanted to kill himself, now he was terrified to die.

The stars were paling, the sky lightening. It should not be long.

What waited after the coin was placed in the dead jaws, after the earth was sprinkled on the corpse, or beyond the flames of the pyre? An eternity of regret, of envy of the living? Perhaps best if the Epicureans were correct, if at last all returned to sleep and quiet.

Something alerted Valens. He saw and heard nothing, but he detected a presence at the mouth of the canyon. He sniffed the air like an animal, but smelt nothing. Despite the chill, he was sweating.

Valens looked over at Iudex. The great domed hairless head had not moved. If his spirit-twin was roaming, it had better return fast.

The blue of the sky was assuming a delicate pink hue. The sun would rise soon. There were no clouds, and not a breath of wind.

A small movement by the cliff at the opening of the ravine, half glimpsed then gone.

They were here.

Let us be men, Valens said to himself.

It had taken no great foresight to judge that the nomads would attack just before dawn, when most men were deeply asleep. Conticinium, the time when birds and animals woke, but men still slumbered. If men were awake, they were at their lowest ebb in mind and body. It was the best time to fall on your enemy, perhaps take him unaware.

If it was a scout that Valens had glimpsed, he would have gone back to report. Valens imagined their low and urgent deliberations. All the gods, let them make their move soon.

The sky was getting lighter by the moment, visibility increasing.

If they decided to besiege the Romans in the canyon . . . No, they would not do that. The tent-dwellers lacked the patience and the stamina. One quick rush was the limit of their tactics. Survive that and their courage drained away. Everyone knew that they had no discipline, would not stand close to the steel for long. Dear gods, let that be true.

Valens heard them before he saw them. A muted rumble of hooves on the hard ground.