I stood in the darkness, listening to the whoops and shouts of the Templars and Fida'in resounding through the main gallery and echoing in the chambers and passages, as the light from their torches flickered dimly on the walls-a phantom army swarming up from the netherworld to plunder the caliph's treasure.

And they would have it, too. There was no one to stop them. Templars and Fida'in together, I thought. On what unholy day had that alliance been forged?

I listened to the sounds of their hurried footsteps as they raced to the plunder… a race I had hoped to win.

I had failed-a truth made more brutal for the fact that I had allowed myself to believe that God was with me, leading me each step of the way, that my trials had been for a purpose, that my suffering had meaning.

But it was all a lie. I knew it now, and the knowledge made my heart writhe like a snake in hot ashes. I could have wept for the futility of it, if not for the knot of hard, hot anger coiling in my gut.

Wazim whispered my name again, gently pulling me from my miserable reverie. 'Look!' he said in a voice half-stifled with awe. 'The holy father is here!'

I turned my head towards the sound of his voice and saw a faint glimmer of golden light reflecting on the surface of one of the stone pillars behind us. It vanished again before I could determine the source. Nevertheless, I moved towards the place and discovered that the pillar stood before the alcove I had examined a few moments ago. The light appeared to emanate from within this narrow, crypt-like room.

Stepping quickly to the low entrance, I saw a man dressed all in white holding a torch in his left hand. His robe was that of a cleric – a priest of an Eastern order, so I thought-and his bearing both lordly and humble, that of a venerated patriarch. I understood at once why Wazim had called him a holy father. Yet, in face and form he was youthful still, his beard and hair black, the glance of his dark eyes keen.

He beckoned me to him, but astonished as I was, I made no move to join him. For, although he held a torch, it was not the torch which shed the light, it was the whole of his being.

Raising his hand, he beckoned me again, more insistently, and said, 'Come quickly, Duncan, time grows short.'

At the sound of my name, I edged forwards a step or two. 'Who are you, lord, that you know me?'

'Duncan,' he said in a tone of gentle reproof. 'Does not the master know his servants? How should I forget one who has served me so well?'

'The White Priest,' I whispered. Wazim Kadi sank to his knees beside me, bowed his head and shut his eyes tight.

'Call me Brother Andrew,' he replied lightly. 'As I once asked your father, so I now ask you: what do you want?'

It seemed a strange question-with soldiers clattering through the main gallery behind us, rushing eagerly to the plunder, what difference did it make what I wanted? Strange, too, his question instantly brought to mind the cool clean breeze of the northern Scottish coast, and I saw the dark waves driven white upon the hard rock shingle of Caithness bay, and standing on the high headland gazing out to sea, two figures: one tall and gaunt, one small, cherubic, her long hair blowing in the wind-Murdo, my father, with little Caitriona by his side-and they were searching the wide, wave-worried sea.

At that moment, I wanted nothing more than to be sailing into that bay, and to hold those people in my arms. 'I want to go home,' I murmured, feeling the tears rising to my eyes.

'So did your father,' replied the White Priest, 'but he was proud and would not admit it.'

'Perhaps he was made of sterner stuff than his unfortunate son.'

'Why unfortunate?' asked the mysterious monk. 'You have the Holy Light to guide your steps along the True Path. Murdo paid dearly to learn what you already know.'

There came a shout at the door of the chamber behind us. Wazim, on his knees beside me, clasping his hands and muttering fervent prayers, jumped to his feet, turned and ran to the alcove entrance.

'I know nothing,' I said, feeling my failure afresh. 'And unless you help us, I will not live to see another morning in this land.'

'O, man of little faith. I will tell you what I told your father the first time we met.'

'What is that?'

'Take heart. You are closer than you know.'

At that moment, Wazim called from the doorway. 'Da'ounk!' he whispered urgently. 'They are coming this way!'

I glanced towards Wazim as he spoke, and as I did so the light in the alcove began to fade. 'What if -' I said, turning once more towards the White Priest. He was gone, leaving only a gently fading glow where he had been standing. But in that shimmering light, I saw that he was right.

'What are we going to do?' Wazim rasped in desperation. 'They are almost here!'

'Peace, Wazim,' I whispered. 'Come away from there.' Taking his arm, I pulled him away from the alcove entrance. 'Brother Andrew has led us to the treasure.'

He glanced around the near-empty room, and then turned frightened eyes on me. 'Where?' he asked.

'There,' I told him, pointing to the vent shaft where an old length of timber was propping open the iron grate. 'He has also shown us our way out.'

As darkness closed around us, I reached up and caught the edge of the shaft opening. I jumped, and Wazim took hold of my legs and boosted me up into the opening, whereupon I scrambled into the shaft. Once inside, I reached down and pulled Wazim up after me. Then, carefully, reverently, I took hold of the short wooden beam and, with Wazim's help, gently eased the heavy iron grate shut. It closed with a dull clank, as two Templars entered the chamber behind us.

They searched the room, sweeping the corners with torchlight and, finding nothing, swiftly moved on. I allowed myself a low sigh of relief, and sat back a moment to catch my breath and reflect on how best to make our retreat. 'Now we go,' I whispered to Wazim.

'What about the Holy Cross?' he asked.

'The search is over,' I told him. 'Here-give me your hand.'

In the darkness, I found his hand and guided it to the scarred length of timber cradled in my arms. Like a blind man, his fingers traced the deep-grooved lines and ridges of the ancient wood, and tears formed in his eyes, and mine, as, each in our own way, we honoured the sacred relic.

The voices of the Templars and Fida'in echoed in the chamber below, and my thoughts turned once again to escape. Of the few courses open to me, I determined that the vent shaft offered the best chance of evading discovery and capture. The ascent was steep, but not impossibly so. I soon found that I could crawl up the incline slowly on hands and knees, pushing the rood before me.

This I did, and a short time later Wazim and I had reached the secret passage above. Although it was as dark as the deepest cavern, I smelled the night-blooming flowers in the breeze from the vertical shaft and knew without a doubt where we were. Standing with my back to the shaft, the tunnel opened out to the right and left. The passage to the right led back to the cistern and the ash-traps below the kitchens; the left-hand passage led to the underground canal.

The canal would take us to the river, thereby avoiding not only the palace and any lurking Templars or Fida'in, but also the overcrowded streets with their rioting throngs. This, I decided, was the way we would go.

Hefting the rood piece onto my shoulder, we started off- one blind man following the other. Wazim walked before me with my bundle of rolled papyrus scrolls slung across his chest, and I followed, keeping my left hand outstretched, my fingertips brushing his back – more for comfort than need, since the passage led in only one direction, without divisions, branches, or turnings; there was no chance of becoming lost.