Turning his head so Sasan would not see the tears in his eyes, Barbad studied the fortress. The outer walls were of dressed stone. The masonry was close fitted and smooth, its surface impossible to climb. On the journey, Barbad had entertained thoughts of escape. They had been nothing but fantasies. The guards had been watchful. Like his father, Sasan had been shackled with silver chains. In any case, how could an elderly eunuch and a young boy hope to escape? Where would they go? To the savage nomads of the northern Steppe? To the Romans far off in the west? Without money or friends, they would reach neither.

At last the gate opened. It was heavy, bound with iron.

As Barbad and Sasan walked into the dark gatehouse, the boy took Barbad’s hand. His skin was warm and smooth in the old eunuch’s grip.

Shafts of light from holes in the ceiling penetrated the gloom. The clomp of the draught horses’ hooves and the squeal of the wagon wheels followed them, echoing back from the walls. Another gate was open at the far end, and they passed into the light of the courtyard.

The castle was larger than it appeared from outside. The curtain wall ran in a rough oval, following the irregularities of the crag. There were buildings against the inside of the wall: barracks to the right, stables and storerooms to the left. Directly ahead a smaller postern stood opposite the main gate, wedged between the barracks and the inner tower. The latter was circular, four storeys high. It had no openings at ground level. Higher, the few windows were small, little more than arrow slits, too narrow for a grown man to fit through. Stone steps were built against its face, climbing from right to left up to a door on the first floor. At the top of the steps, the warden of the Castle of Silence stood waiting.

Naduk, the zendanig, was a huge man with a broad red beard that spread across his chest. Barbad had seen him before at the royal court. As befitted his gloomy occupation, Naduk always wore dark clothing. No zendanig was ever loved, but such was the air of menace that hung about Naduk, even in the entourage of the King of Kings, men shrank from his presence.

Barbad and Sasan ascended the steps. The boy went ahead, walking calmly, holding himself straight. Again the young prince’s courage threatened to rob Barbad of what manliness the knife had left.

‘Welcome, Prince Sasan, son of Prince Papak, of the House of Sasan.’

The warden’s eyes were cold and black, like pebbles in a stream. His words were polite but there was no compassion in his voice.

‘Your accommodation is on the upper floor.’

‘You are most kind,’ Sasan replied.

Naduk turned and led the way. The guards brought up the rear.