Prologue

Tabriz, northwest Persia, July 1934

Above the ornamented clock tower of Tabriz City Hall, the air shimmered in the heat of the summer noon, as the streets below bustled with lunchtime activity and the spices and smoke of the markets crept along the narrow alleys of the old town. In many respects, it was no different to any other city along the ancient Silk Road route - the bazaar, one of the oldest and largest in the region, was filled with the cries of the merchants selling the famous Tabrizian rugs to customers from far and wide, while in the Valiasr quarter the scent of the local kufteh and dolma lured visitors in for a meal, and soon the call of the muezzin from the minaret of the partially-destroyed Blue Mosque would bring people to prayer.

Were it not for the stranger currently picking his way through the carpet sellers of the Mozzafarieh, it would have been a normal day for the people of Tabriz.

The stranger was not Persian, nor even Azerbaijani - his short fair hair, pale sunburnt skin, scrubby ginger beard and clothing rumpled and dusty through days of travelling told of a more Western origin. He might have drawn less attention to himself if he did not stop to ask directions from passers-by, speaking the local dialect fluently, or if he did not keep a vicious-looking whip coiled and ready at his belt. He wore a battered brown fedora at a jaunty angle, and despite his slight build and diminutive stature, the mismatched blue eyes that shone brilliantly from beneath its brim said plainly that he was not a man to cross.

There were merchants in the Amir Bazaar who knew that Indiana Thom was in town. The man's reputation preceded him: he had no interest in pretty trinkets, not in their gold and jewellery, and he would not be there for Tabrizian rugs. Those who ran a small trade in marketing forged cuneiform tablets to gullible treasure collectors were not safe; there were rumours that he was some kind of respectable academic in his homeland, perhaps a Doctor or a Professor, but indeed an expert in all periods of Sumerian and Akkadian language and history, and also in identifying fakes. There were often secret jokes shared between the merchants about Indiana Thom, for the cultures of ancient Mesopotamia were hardly a fashionable or glamorous field of study when the western world was currently obsessed with the Minoan and Mycenaean civilisations of the Mediterranean; not that any of of them would have said this to the man's face, when he was formidable not only in an intellectual capacity.

Mr Khan was one such merchant. He was in fact a Pakistani by birth, but this lent his own business a slightly exotic flavour. He specialised in fine art and jewellery from his own country, but also in rare archaeological artefacts such as Sumerian pottery and arrowheads, Babylonian scripts and Akkadian seals, which attracted interest not only from local enthusiasts but academics further afield; hence the appointment he had arranged with this Doctor or Professor Thom, in which he was hopeful of coming away considerably richer than he had arrived at the bazaar that morning. It didn't stop him from being apprehensive when the man in question approached the stall, knowing that he himself lacked the expertise even to know whether what he intended to sell was genuine or fake, and that the majority of the academic world was divided on whether the culture to which this piece purportedly belonged had actually existed in the first place.

It threw him off even more when the man spoke flawlessly in the local Azerbaijani dialect, although he knew that he was a linguistics expert. "Mr Khan? I was told I'd find you here. I'm Dr Thom, from the University of Oxford - we spoke briefly over the telephone last month about a piece you were hoping to receive from the excavations at Tell Abu Shahrain."

Khan inclined his head to indicate the affirmative. "You received the telegram? I wasn't sure that the... ah... the article would arrive in time for our meeting, but it was delivered to me yesterday. Will you want to see it?"

"Naturally," Dr Thom said, with a small bite of impatience in his voice that was evident even in his heavily accented speech. "I have seen a considerable number of forgeries from the period - they're far more common than the genuine pieces, sometimes more convincing than the real ones, but you claimed that this was certainly authentic?"

Khan shifted uncomfortably, hiding his face as he reached beneath the table separating the pair of them to withdraw a small wooden box, less than a foot wide from corner to corner, carefully nailed shut and marked on the lid with stamped Arabic script. "I'm not certain, but I have it on good authority. Hall - rest his soul - did write that there were very unusual sherds coming up from some of the trenches..."

Dr Thom waved an impatient hand. "Yes, yes, I know about that. I was acquainted with Dr Hall before his death, he studied with my father in Oxford although his interests lay more with Egyptology than Sumerology, more's the pity... anyway," he continued, withdrawing a penknife from a pocket of his loose shirt, "let's see what we have, before we get carried away."

He flicked the knife open and slid it into the narrow gap beneath the lid of the box, delicately levering it open. After shifting aside a few layers of shredded paper and sawdust, the shape of a small, heavily decorated and polished red clay pot sherd became clear. To Khan it did not appear to be anything special - pot sherds were two a penny to someone in his line of work, and aesthetically it was no different to a hundred other sherds he would sell over the counter in an ordinary day. However, to Dr Thom it was evidently much more important than it looked, for he gently blew away the remaining sawdust and bent closer, taking out an eyeglass and holding it up to examine the sherd in greater detail.

Eventually, Dr Thom put away the eyeglass and lifted the sherd from the box, turning it over in his hands to study the cross-sections along the fractured edge, seeming to hold his breath as he squinted at the striations in the clay and ran his fingertips over the cuneiform lettering surrounding the etched patterns on the sherd's surface. "Whoever your contact is concerning Tell Abu Shahrain, they have no idea what they are doing," he said abruptly, replacing the sherd in the box and covering it again.

Khan's heart sank. "It's a forgery?" he asked, trying not to sound too disappointed.

Dr Thom shook his head, a smile starting to form on his lips. "Not at all. It's perfectly genuine. Mr Khan, if the script on this sherd is what I believe it to be, you will have played a key role in the most important archaeological discovery of this century, if not this millennium! This is like few things I have ever seen in this profession - evidence of a pre-Archaic Sumerian civilisation -"

He got no further than that, because at precisely that moment there was the unmistakable crack of a nearby gunshot, and when he raised his eyes to Mr Khan's face again, it was to find the empty gaze of the Pakistani merchant staring back at him while blood started to spill from the perfect wound dead in the centre of his forehead. Someone screamed, and almost instantly their voice was joined by another, and another; Dr Thom snatched the box from the table and slipped it quickly into his knapsack, before slinging it over his shoulder and turning to see where the shot had come from. It was not hard to see; at one of the windows below the vaulted roof of the bazaar, a figure clad in concealing black robes crouched, taking aim for a second shot at Dr Thom himself. The Doctor wasted no time in retrieving the Webley hidden in his belt and firing, forcing the assailant to take cover and affording him time to duck into the maze of stalls and shoppers that filled the halls of the bazaar.

He was left in no doubt that one of the witnesses to Khan's murder would alert the city police, and his having fled the scene would put them in mind that he was the culprit. But he had no intention of staying to meet the same fate as the unfortunate merchant: he had anticipated that there would be some sort of attempt to steal the pot sherd, for news often travelled fast where such things were concerned and there were many less scrupulous than he who would stop at nothing to get their hands on valuable, possibly pre-Sumerian artefacts. Even within the academic community there were those who were little more than glorified grave-robbers, and he liked to consider himself a cut above such people; his was an interest in the culture that such artefacts represented, absurd myths about pre-Sumerian civilisations aside. In any case, he had his own last-ditch method of escape to fall back on; it was unnecessarily dramatic and showy, but it appealed to his sense of adventure as much as anything.

Distant shouts told him that the police were already on their way. He pushed through throngs of haggling women and opportunistic children who upon seeing a Western face would snatch at his clothes, clamouring for a hand-out, but he ignored them and pressed on, calling hasty apologies as tables of gold chains and semi-precious stones went flying and he attempted to keep a hold on both the Webley and the knapsack. It was the police at the other end of the bazaar who stopped him dead in his tracks; upon their seeing him a loud cry went up and heads turned in his direction, and he muttered a curse under his breath. The only way out was up.

He shoved the Webley back into his belt and, ignoring the protests of the angry owner, clambered up the wooden framework of the nearest stall to reach the ledge of the window above it. He wasn't particularly concerned about the police trying to shoot him down - they wouldn't take the risk with the bazaar as packed as it was, but it didn't mean they couldn't make life extremely unpleasant for him if he was caught, especially if they considered him the prime suspect in a murder.

The window was of heavy, leaded glass that would not easily be smashed by the force of a strategically placed elbow; a close range gunshot would be a decidedly dangerous undertaking in such a situation, and he looked around in desperation to see if there would be anything that could aid his escape. His eyes fell on the metal brackets from which the lights of the bazaar were hung, and an idea formed immediately in his mind; he put a hand to his belt to uncoil the whip, mentally measuring the distance to the overhead bracket and judging the necessary force required. One whipcrack later and the tail end of the narrow leather strip was tightly curled about the bracket, and just as the nearest policeman reached the stall below the window Dr Thom jumped from the ledge, booted feet thrust forwards to smash the panes of the opposite window. Cheers and exclamations followed his progress as he retrieved the whip and set off across the rooftops, slipping and sliding on sun-baked clay and hot tiles that fell away beneath his feet when his jumps bridged the gaps of narrow passageways.

There was the shrill of a police whistle, and a clatter of bullets ricocheting off the brickwork at his heels as he leapt across an alley which was wider than he had anticipated. He missed the edge of the next roof by mere inches, clinging to slates that gave under his fingers, scrabbling for purchase with knees and feet and hands before the gutter snapped with his weight and he was falling, falling, falling... and then flying as something smacked into him and he grabbed onto it instinctively, feeling the smooth wood and rough rope of a hanging ladder that had seemingly dropped from nowhere straight into his arms. Glancing up as he soared free of the densely populated streets of Tabriz, he could see the sand-coloured fuselage of a small two-seated biplane from which the ladder was suspended, and clung more tightly to the knapsack as the plane and its unusual passenger were whisked away into the mountains.