When we were alone I stood silently before him awaiting his words. But he took my arm without speaking and walked with me to the smaller chamber that lay beyond, where his notary and scribes did their work, and through this to his own cabinet, closing the heavy door behind us and leading me to the narrow space within the embrasure of the window.

It was no more than the habit of caution, bred by his many years in the palace service. I did not take it to mean that the matter was serious, nor did his first words give me any indications of this.

"Well, Thurstan Beauchamp," he said, "is that a new sorcot I see this morning?"

"Yes" I said, "so it is."

He made game of me sometimes about my extravagance in dress, using, with an accent of irony, the French terms that had become fashionable of recent months in Palermo. I like to be clean and neat and make a good figure and I took much care with my appearance, shaving twice every week and spending a good part of my stipend on clothes and scent and oil for my hair, which is very light in colour and reaches to my shoulders. That morning I was wearing a coat of dark blue silk, padded at the shoulders and pinched in the sleeves.

"And the chainse, that too? And the chauces?

He smiled as he spoke and I returned the smile, knowing these questions were a way he had found of showing affection for me. No, I told him, the shirt was not new, but more of the embroidery showed because my new coat was cut low at the neck. I was rather relieved that he made no jokes on this occasion about my singing. He had discovered – but he discovered everything – that I had a good singing voice and a good stock of songs both sacred and profane. He threatened sometimes to set me singing through the corridors of the Diwan, to enliven his work people.

"Yes, I see," he said. "Cut low at the neck, very striking." He himself dressed always with utmost simplicity, in white robe and high white turban and girdle of green silk, with for only ornament an emerald pin at his collar. Secretly I thought he made the better appearance, because he was also slender and graceful in movement, whereas I have more weight to me and more thickness in the shoulder.

His smile faded now and he looked at me more closely. "There is a mission for you," he said.

I should pause here to say something more about this Diwan al-tahqiq al-ma' mur, which some called the Diwan of Control, and others the Diwan of Secrets. It is the central financial office of the palace administration, responsible for tax registers and for confirming grants of land and villeins out of the Royal Demesne. Much power lies in this chancery, since the royal grants and renewals of privilege can only be issued by its officers and not by the ordinary officers and scribes of the Royal Diwan. It is also concerned with the more secret operations of money, the management of blackmail and bribes, which both come under the heading of inducements, and the gathering of certain sorts of information, regularly reported by Yusuf in private audience with the King. Like all those who served in the palace chanceries, we took care to keep certain activities from public knowledge – and more particularly from the knowledge of other chanceries. Much of my work lay on this darker side. It was the King's policy to use bribes wherever possible; I was one of his pursebearers, and this consorted well with my official duties as purveyor, since my travels could always be explained as being in quest of new pleasures and shows.

"As you know," Yusuf said now, "we continue to have close relations with the Kingdom of Hungary." It was usual with him to begin with what was commonly known. Coloman, King of the Hungarians, was married to our King's cousin, Busilla, and all knew there was close friendship between the two thrones. "We are still receiving assurances that the Hungarians are ready to support an uprising in Serbia, if this could be brought about."

Yusuf's face was thin, and always seemed thinner by virtue of the tall, dome-shaped turban. His eyes were dark, set deep in his head and very penetrating. They rested on me steadily, on a level with my own – he was tall for an Arab, as tall as I, though slighter, as I have said, and narrower-boned. "Actively support," he said after a moment, still looking closely at me.

My heart had been sinking ever lower since the mention of Serbia: I was already suspecting the nature of this mission. "My lord," I said, "how many times have we heard of this readiness of theirs?"

"True, but this time there is more ground for belief in it. We have it from sources close to the throne and it is confirmed on the Serbian side. Hungarian cavalry units are massing on the border. The train is set. We are waiting only for a spark."

I nodded but made no immediate reply. This spark, so much awaited, was a Serbian uprising against Byzantine rule. This, aided by the Hungarians, who were eager to extend their eastern borders, would distract Manuel Comnenus, oblige him to send troops in Serbia to put down the rebellion, and so turn his attention from his plans to invade Sicily.

Privately I no longer believed either in Serbian uprising or Hungarian intervention; both had been promised so often before. Now I would have to travel somewhere to meet Lazar Pilic, the only Serbian rebel leader who spoke Greek. I did not trust Lazar and I knew that wherever this meeting took place it would mean an uncomfortable and probably dangerous journey. To be sure, the danger to Lazar was greater. Byzantine rule in the Balkans was not secure. They felt the ground shifting, they feared for their footing and so they became more watchful and more cruel.

Blinding – the usual punishment for traitors and spies – was the least Lazar could expect if he came under suspicion.

The real difficulty lay in the fact that our Diwan did not have full scope for action in the Balkans, being restricted to the payment of bribes. Elements in the Vice-Chancellor's Office had formed a separate chancery which they called the Diwan of Command, a title confusing in its similarity to our own. They had gained the ear of the King and been granted the mission of diplomatic persuasion in Hungary. We had to rely on their reports, which came to us in garbled form with much that was significant omitted. Sometimes they did not come to us at all. So there were now two branches of the administration separately involved in fomenting rebellion in Serbia, each jealous of the other and neither sharing their information.

"We have already disbursed a good deal of the King's coin on these Serbs," I said. "So far without result. We do not know how they spend the gold, we have no means of knowing."

"This time there will be no gold. So far they have taken with both hands and made promises that were not kept. Now we in our turn will make promises, but we will keep our hands hidden."

He smiled a little, saying this; he had the Arab love for word-play and reversed figures. I for my part felt some beginning of relief. He had spoken of a mission, but where was the mission in this?

"If we are to refuse them, there is no need for a meeting," I said.

"On the contrary, there is every need. If you are there in person to refuse, it will strike them the more. You are there, before their eyes.

You are only the reach of a hand away. They reach out their hands, and lo, you give them nothing. The situation is serious for us; perhaps by these means we will make it more serious for them."

His tone had deepened slightly during these last words, a sign of feeling which he was perhaps not aware of. There was a gesture too that betrayed him. He wore as a talisman a scroll inscribed with the 99 names of God in an embroidered leather case carried on a silk cord that passed over his left shoulder and across his body. In times of anxiety he would touch this case, brushing it slightly with his fingers. Unlike many of the Saracens in the Royal Diwan, who had converted to Christianity, Yusuf had kept the faith of his fathers.