Thus, we made our way to the secret stream, stumbling now and then, but proceeding with good speed. The sacred relic was heavy and unwieldy, but after carrying Bohemond's head all that time, I had learned how to bear a burden without tiring myself unduly. And, after a time, I found I did not greatly mind the darkness; although I was blind as a stone, I knew the canal lay just ahead, and that there was a boat waiting to take us to the Nile, where at long last I would be reunited with Padraig and the others.

In a little while, the downward trend of the passage increased and we came to the first of the series of low steps-first one, and then two, and so on, until I could hear the ripple and splash of the stream ahead. We checked our pace, and continued with greater caution, arriving at the water's edge at last. Passing the rood to Wazim, I knelt down on the last step and felt along the edge of the wall for the ring to which the boat was tethered. After much fumbling, I found the ring and then set about untying the rope.

It was knotted tight and there was no loosening it. The braided cord, however, was old, and scuffing it against the brickwork of the passage it soon frayed to the place where, using all my strength, I was able to pull it apart.

Wrapping the end of the rope around my hand, I pulled the boat to the steps and instructed Wazim to lay the rood down on the path behind me, and get into the small craft. 'I will steady it for you,' I told him. 'When you are ready, I will hand you the rood.'

Slowly, and with exaggerated care, we settled Wazim in the boat, and I handed him the rood, telling him to hold it upright and clenched between his knees, keeping one hand on it at all times. Then it was my turn; I was able to get in without capsizing our vessel, and allowing the stream to turn us, I released my hold, pushing away as the bow came around.

The flow of water was not fast and the boat glided away slowly. It was strange, floating along in utter darkness. But for the gentle stirring of air on our faces, we might have been sitting completely still in the water. From time to time, I dipped my hand in the stream to test that we were indeed moving along with the flow. Once we bumped against the side of the canal-which startled both of us, and caused Wazim to cry out in alarm. I was able to push away without incident and from then on kept one hand out so as to fend off another collision.

Unfortunately, the damage was already done. The boat was old, the wood rotten, and the impact, though mild, had loosened part of the hull and caused a seam to open, allowing water to seep into the boat. The first I knew of it was when I felt my feet getting wet; I put down my hand and realized the bottom of the boat was awash.

'Stay very still,' I warned Wazim. 'The leak is slight, and we may yet reach our destination before the hull fills with water.'

That was not to be, however. Soon water was sloshing over our ankles. Bailing was futile. Although I tried for a while, cupping my hands and flipping it out by the handful, I could not keep pace with the rising water. 'Can you swim, Wazim?' I asked.

'No, master,' he replied, his voice taking on a quaver of concern.

I assured him that I could swim well enough for both of us and that there was nothing to worry about. I was still offering this assurance when the boat struck the canal wall again and the seam opened wider. I felt the water rising, and said, 'Listen carefully, Wazim. I am going to get out of the boat and into the water. Stay just as you are, and do not move. I will hold to the side of the boat and all will be well.'

This was far too optimistic, however; the darkness complicated everything-even simple movements became manoeuvres fraught with difficulty. In the end, I succeeded in sliding over the side without overturning our fragile craft. The water was not overly cold, and I reckoned that by removing my weight from the boat, we just might make it to the river before the vessel sank.

We struck the side two more times in quick succession, and the second bump spun the boat around. Despite being in the water, I was able to keep the vessel from overturning, and perhaps we would have made it to our destination intact if the current had not picked up markedly at the same time. I could not see what caused the stream to move more quickly, but thought it must be that the walls of the canal had narrowed.

And then, in the distance, I heard the rushing splash of falling water. Not wishing to alarm Wazim, I said, 'I think it would be a good idea to join me now.'

'I am happy to remain in the boat, Da'ounk,' he*replied, his voice trembling in the darkness.

'I think you may have no choice, Wazim. I want you to hand the rood to me first, and then ease over the side. We can hold to the rail. The boat will float a long time yet, even with water in it.'

I could feel the stream beginning to swirl around me as the current strengthened. The rushing sound grew louder. In the dark, it would be impossible to judge the severity of the drop, or even to know how far ahead it lay. I kept this to myself, however, as I did not wish to frighten Wazim the more. 'Here,' I said, tapping the rail with my hand, 'let me take the rood, and then I will help you over the side.'

Muttering in some incomprehensible tongue, he passed the holy relic to me, and then prepared to ease himself over the side. Gripping the side of the boat, he made to stand and at that moment I felt the bow veer sharply away; the boat struck the wall of the canal and poor anxious Wazim was thrown off balance. He gave out a terrified yelp and released my hand as he fell back into the boat.

I heard the dry crack of rotten wood. There was a shuddering splash and the fragile craft began to break apart. Grappling with chunks of wreckage, I shouted for Wazim and made for the sound of his thrashing and coughing.

All at once the water surged around me. I felt the floor come up sharply beneath my feet, and floundered for a foothold. Chunks of stone scraped my knees and shins as I was dragged forwards by the force of the water. I shouted for Wazim to keep his head up, and then felt a rising swell like that of the open sea as I was swept over the falls.

Holding tight to the rood, I plunged sideways and struck a jumble of stone blocks on the bottom of the stream bed. I was tumbled along beneath the surface of the water, pummelled by pieces of wreckage as the ruined boat came sliding over the falls. The Black Rood slipped from my hands as I was rolled over again and again by the force of the water.

All was darkness and turmoil. I could not tell where I was, nor which way to the surface. I flailed underwater, desperate to rise, but the stream went on and my lungs felt like they were on fire. My chest ached. I must soon breathe, or burst.

And then I collided with something hard-a dense and solid mass, moving with me in the water. Even blind and confused, I knew it was the rood. I threw my arms around it and let it guide me to the surface.

I clung to the Holy Rood, gasping, gulping down air, and thanking the Swift Sure Hand for his timely deliverance.

I felt something squirming in the water as it slid past; I snaked out a hand and snagged the edge of Wazim's robe, and pulled him up. He spluttered and coughed, and thrashed around wildly.

'Peace, Wazim!' I shouted. 'I have you now. Be still. You will not drown.'

I had to repeat this several times before he ceased struggling; but eventually the fight went out of him and he allowed me to bear him up.

Holding to the rood with one hand, and to Wazim with the other – while at the same time trying to keep my head above water-I could do little more than drift with the current, and this I did, until the stream began to lose some of its force and turbulence. We bobbed along for a time, until I struck the side of the canal with my foot. Releasing Wazim for a moment, I fumbled in the darkness for a handhold on the rough stonework. 'Here, Wazim,' I said, dragging him to the wall. 'We are saved. Grab hold and hang on.'