"By whom?" the Prince demanded sternly. "By the other party to the Treaty -- I assume. Either that, or else we have here the first recorded case of temporal interference by a time-traveller from some place not bound by treaty obligations." There was a terrible silence in the audience chamber. "You realise," the Prince said at length, "that this is the most serious allegation you could possibly make?" Would I did not! But Don Miguel kept that thought to himsell, and merely nodded. "You have grounds?" "I believe so, sir. Having conducted such on-the-spot investigations as were possible to me without time apparatus, I could come to no other conclusion." The Prince put out one hairy-backed hand towards the harmless-looking chip of metal on the table before him. At the last moment before completing the gesture, he drew back as though from a sleeping snake. He said, "Clear the hall! At once! And if anyone breathes a word of this I'll have his head off his shouders before nightfall -- is that clear? Executioner! I know there are at least three incurable gossips whose tongues rattle day and night like dry peas in a bladder -- have three stakes ready by this afternoon to mount their heads on!" The man who stood by the door, black-masked and anonymous, bowed to acknowledge the order, and not a few of the courtiers shivered. "Now get out!" barked the Prince. "All of you except Don Miguel, and make it fast!" The Treaty of Prague, Don Miguel had often thought, was the most fragile bulwark ever interposed between man and the forces of primal chaos. It was like a plug of wet paper in the mouth of a volcano -- yet it was the best they could contrive. At the first moment when Don Carlos Borromeo discovered how time might be converted into a direction like other directions so that men might make voyages along it, he -- whom some called very wise, others incurably bitter and disillusioned -- had clearly foreseen the uses to which selfish and greedy men might put this miracle. Allegedly he had considered trying to suppress the knowledge altogether, but in the end, after consultation with his confessor, he had been compelled to accept that someone else might stumble on the same principle who was less sceptical about the ability of mankind to cope with powers beyond their previous dreams. But, looking at the contemporary world around him, he had been faced with those intransigents who wished to reconquer Spain, the old beartland from which Christian civilisation had been driven by its virile Islamic rival, and who would not have been above sending back an army to ensure that alteration of history. Similarly there were those in the fretful, unstable Confederacy of the East who resented being part of a heterogeneous political alliance, and who would rather have seen Lithuania, or Poland, or Prussia, or even Russ, become an unquestionably dominant national power free from the need to consider the wishes of competing local interests. Putting time-travel into the hands of men with such a background would be like smoking a tobacco-pipe in a powder-factory. The best that could be hoped for, he decided, was that the technique of time-travel should be administered by men with proper scruples, aware of the responsibility their knowledge imposed on them and bound by oaths to obey the instructions of the wisest and most far-seeing officers who could be found to lead them. Accordingly, having appealed to the Pope for a commission that empowered him to dictate to princes, kings and emperors under pain of instant excommunication, he set up the Society of Time and pledged its founding members to employ time-travel solely for the benefit of mankind, to increase the sum of human howledge and not to interfere with the past. Nonetheless, what he was afraid of happened: almost at once a party of lunatics began to agitate for the reconquest of Spain. For a while it looked as though madness would overcome sense. Then, however, the balance was tipped back in favour of rationality. The Confederacy let it be known discreetly, delicately --- that they too had gained the secret of travelling in time. If an Imperial army went back to oppose the Moorish invasion of Spain, it would be met by corresponding forces determined to keep the status quo --- for the Confederacy regarded the Empire as quite strong enough already without the retrospective addition of the Iberian peninsula to its territory. It was whispered, but never proved, that Borromeo himself had given his secret to the Confederacy. At any rate, it was for the best; the Empire came to its senses, proposed Papal arbitration, and with the assistance of the Vatican's finest legal experts drafted the agreement which was ultimately signed in 1897 in the handsome and ancient city of Prague. The Treaty was Borromeo's last legacy. Three weeks after it was signed he died of a chill caught in the mists of Poland, for it was a bitter winter that year. Perhaps, thought Don Miguel, he had died content. But it seemed unlikely. He must have suspected that sooner or later the Treaty by itself would prove inadequate, even though it plugged the dyke for a little while. He might not have foreseen that greed would so rapidly corrupt the very Licentiates who were supposed to be chosen for their honesty and integrity -- yet Don Miguel knew, better than any of his colleagues bar Father Ramón, how near ordinary greed had already come to oversetting the fabric of history. Over and above that, though, there was the even more significant point that Borromeo must have been aware of: time apparatus was intrinsically so simple that eventually other scientists whose governments were not signatories to the Treaty would chance on the principle involved . . . or be sold the information by someone venal, someone with a grudge, someone mentally unstable. Was the discovery which Two Dogs had made the first evidence in the twentieth century that some other power was due to develop time-travel? Would it prove to be an expedition from the Mediterranean Caliphate that was involved, or -- more likely, considering the geographical location -- temporal explorers from the Middle Kingdom of Cathay? Or intruders from Çipangu, those islands off the eastern coast of Asia whose people so greatly admired the Empire and who sought to turn their geographically analogous location into a politically analogous independence from the mainland culture of Cathay which had dominated virtually their entire recorded history? Don Miguel doubted these latter possibilities. He was a great believer in the principle enunciated by William of Occam, the "razor" which advised one not to multiply assumptions more than necessary. And here one did not have to assume. One merely had to deduce . . . "It's good steel," he said, pointing to the object on the table between himself and the Prince. "It's the bit of a rock-drill, cracked in half. I've established beyond doubt that we've never mined that valley. And history shows us no one who knew how to make good steel and who passed through that part of California prior to our discovery of the New World. In company with Two Dogs, the mine manager, I searched the locality for several miles around. We discovered the traces of at least nine mine galleries, all bar the first caved in. Two Dogs has extensive grounding in mineralogy; he was able to estimate that these mines were worked approximately a thousand years ago. I spoke to several of his foremen and overseers, and they took me to see abandoned galleries of their own where what should have been extensive veins of ore had turned out to stop short instead of continuing for the predicted distances. It was that which finally drove me to the inescapable conclusion that we're here faced with an illegal intrusion into the past." The Prince gave a slow nod of comprehension, his face bleaker than winter in Norroway. He said, "By whom and for what purpose, Navarro? What's your view?" "Sir, I can only interpret what I've seen for myself." Don Miguel licked his lips. "I read the situation like this. It's notorious that these hills are among the richest mineral deposits in the world. I think the intruders decided to exploit them -- perhaps for some metal, such as silver, which is essential to time-travel. In the present this was impossible, since we're already at work there, but in the past, of course, the area was empty, bar a few naked Indians with no interest in mining. Perhaps they were, or are, not very experienced in geology, and took it for granted that when they had finished their work it would suffice to rely on natural causes to wipe away the traces of what they'd done. After all, California is earthquake country, and in a thousand years you'd expect mine galleries to cave in of their own accord. It must have been sheer chance that preserved the one in which Two Dogs discovered the drill-bit." "So this thing" -- the Prince picked up the scrap of steel -- "has been lying in the ground for a thousand years! Yet it's barely marked with rust, isn't it?" "As I said, sir, the mouth of the cave -- of the mine gallery, rather -- was closed by this balanced boulder. Earth and grass-roots had made an almost perfect seal around it, and the interior of the cave was dry. In any case the climate there is equable." For some moments the Prince was silent. His dark eyes searched Don Miguel's face. At length he said heavily, "I wish it were not so, Navarro, but in my judgment you've made out a case. We'll get time apparatus to California as quickly as we can, and see if we can secure objective evidence." He rose to his feet. "Meantime, we'll also notify Londres, and bring out our most highly trained investigators. I'm not questioning your analysis of the situation, but you must appreciate that an unfounded charge concerning a breach of the Treaty of Prague could ruin the precarious trust we've managed to nurture between ourselves and the Temporal College." "Sir," Don Miguel said with feeling. "I pray that I am wrong! For how much more disastrous it will be if I'm right!" IV Before the discovery Of humane drugs to unlock the gates of truth in the human mind, there had been a torture -- used even by the Holy Office -- consisting in the placing upon the subject of a large wooden board, and in turn upon the board a succession of stones of increasing weight, so that in the end a stubborn man would be crushed like an insect beneath a boot. For Don Miguel the next several weeks were like a session of such torture. And he was not the only one to suffer. The first of the stones was a light one, and added nothing more to his burden of anxiety than simple confirmation of what he had already suspected. It had been rumoured for some while that more gold and silver were circulating in the Confederacy than their known resources could account for. The logical deduction was that new and so far secret lodes had been located, perhaps in the inhospitable unexplored wastes of Siberia. Present information made it seem likelier that for "Siberia" should be substituted "California" . . . The second stone was header and more painful. A metallurgical expert compared the mysterious drill-bit with samples of other steels, and reported unequivocally: made in Augsburg! It was of a type commonly used in the Confederacy, but hardly ever encountered elsewhere -- certainly not in California, where a number of the trace constituents, notably cobalt, were unavailable. The third, and heaviest, was a report from a team of men whom Two Dogs -- at Don Miguel's urgent request -- had set to searching the route between the site of the poachers' mine and the nearest convenient harbour on the coast. One of the earliest questions to have arisen, naturally, had been this: how did the poachers reach the site where their traces had been discovered? It was of course possible to operate a time apparatus to transmit its occupant spatially as well as temporally -- all that was required was an adjustment of the dimensional relationships dictated by the power-carrying bars in its frame. So long as the gravitational potential at the arrival point was roughly the same as that at base, no harm would come to the traveller . . . although transmitting from a hilltop to a valley resulted in the messy dispersal of surplus potential energy and the death or injury of the victim. Yet it seemed improbable that one should voyage blind across a thousand years and also displace oneself by several thousand miles; it would be a fearful leap into the dark, and there was the risk of the shape of the landscape having been changed by erosion or earthquake, so that one might arrive inside a hill, or in mid-air. It seemed more likely that the poachers must first have gone back in time at some place whose topography they could establish beyond doubt, and then at least a scouting party would have proceeded to the mining site by more conventional means. And the men dispatched by Two Dogs, following the most obvious route to the sea, came across a shlp's timber buried in the sand, of a form not commonly employed by the aboriginal inhabitants and in a condition to suggest it had been lying where they found it for some such period as a thousand years . . . Driven almost to a frenzy by the cumulative pressure of this news, the experts sent out from New Madrid and Londres by the Society of Time redoubled the pace of their preparations. Transportable time apparatus was brought to the lonely Californian valley under habitual conditions of secrecy -- few people outside the Society ever saw an actual time apparatus, because it was so dangerously simple, being composed only of bars of silver and magnetised iron in precisely determined relationships. It might have entered someone's head to make a model of what he had seen, with the disturbing consequence that the model might work . Accordingly, a small town of canvas marquees bloomed in the sunlight, and the labourers and their families went by incuriously for the most part, occasionally pausing to watch, but not often, as yet one more manifestation of the madness of these Europeans intruded into their quiet private world.