Valens thought for a time before he spoke. ‘You must hate your husband’s brother. Having told us that, you know what will happen to him at our hands. The persuasion will not be gentle, although we will not kill him unless it is essential.’

‘I would be happy to see him dead, but it is unnecessary.’ She looked into Valens’s eyes. ‘I also have been to the Caspian with my husband, and know the passes as well as any merchant.’

‘No.’

‘You must take me with you.’

‘It is impossible.’

She looked away. In the lamplight her face appeared longer, the bones more pronounced, like that of a man.

‘You have to take me with you.’

‘We do not.’

‘If I go with you, there will be no outcry. But if you leave me here, the whole of Persia will be on your tracks.’

Valens said nothing.

‘You see, I know why you are here.’

‘We are merchants.’

‘No, you have been sent to rescue . . . someone . . . from the Castle of Silence.’

‘What makes you think that?’

‘Zabda told me before he died.’

Chapter 21

CHAPTER 21

To the Caspian Sea

THE RIDER WAS WAITING AT the head of the pass, where the track ran between towering crags on one side and a vertiginous ravine on the other.

Although it was too far to make out the individual, Valens knew it was her.

‘It is not an ambush,’ their guide said. ‘This is a dangerous place, but brigands would lie concealed up on the heights.’

No, thought Valens, not an ambush for us, but a most unwelcome turn of events for you.

They plodded up the long rise. The horses were weary, and their heads were down as they negotiated the incline. It was late in the afternoon, and it had been a long day’s ride since they left the village at dawn. They would make camp beyond the pass.

So far the guide had not attempted to lead them astray. That treachery would be planned for deeper into the wild mountains that barred the passage from the Tigris to the Caspian. The brother of Lucia’s dead husband was a merchant, and he spoke Greek. He had an abrupt manner and an untrustworthy face. Did not some philosophers say that all trade involved cheating? Merchants bought goods cheap to sell them at a profit. On this journey, the man had a more deadly deceit in mind.