These preparations were unnecessary. No one was ever to come forward and claim kinship with Guy, nor did Guy himself now show the slightest signs of turning his back on his past. Though he spent the long vacation getting such work as he could to help pay for his clothes and extra expenses, he returned every Christmas and Easter, changing as the train steamed over the Tyne Bridge into his old ways and old dialect as easily as one changes coats. At nineteen, Guy Farne was still on the short side, still trailing his extraordinary strength and compactness as though his muscles were of a different clay. The springy dark hair, the pointed ears which Martha had bandaged to his skull in vain, combined with his high cheekbones to give him that puckish, foreign look that in the orphanage had been laid at the door of the Lithuanians, but his wide mouth and strong chin recalled a simpler, more pastoral heritage. Guy’s eyes, during those years at Cambridge, were seldom without the glint of blue which signalled the well-being of his soul as he came into his own in scholarship, in sport and friendship. Only women he left alone, knowing — as men whose sexual power has never been in doubt do know — how to wait.

He got a First and went to the University of Vienna which, in the year 1911, was unrivalled for its work on the conduction of metallic ions through water. Martha Hodge never knew what happened during that year for which he left bursting with confidence and from which he returned, green-eyed and taciturn, with the information that he was no longer interested in academic life and had thrown up his studies. That he had been deeply hurt was obvious; that it was by a woman she did not find it difficult to guess. Wisely, she held her tongue and received, with her usual quiet attention, the information that nothing mattered except to be extremely rich.

The first million, they say, is the hardest. Guy made his by selling to the house of Rothschild (one of whose youthful members he had known in Vienna) a detailed and audacious scheme for the forward purchase of options on cargo shipping rights. Based on the prediction of a war which, owing to the almost equal balance of power in Europe, would be long, and presented to the amazed old banker in a red student’s exercise book which was to become a family heirloom, it provided at minimum risk — for the down payments to the shipping companies were to be regarded as interest-free and recallable loans — an opportunity to corner the charter market within five years.

Extorting his reward, under the threat of publishing the details of his scheme, Guy left for South America where he spent three months exploring the backward and mineral-rich Minas Cerais. Within a year he had extracted from the Brazilian government an option on the mining rights of the Ouro Preto range, offering in exchange foreign investment and the building of roads and schools for the Indians. It was not the gold and emeralds which were his chief concern, but the cobalt, for he foresaw the western world’s insatiable demand for high-grade steel.

Thus, in those first years, he established a pattern which was to make his success a legend: the use of his scientific training to predict events, the nerve to back his hunches and the direct and practical entrepreneurism of the man on the spot; for he was always to return to the products of the earth’s crust and the adventure of their extraction.

By the time war came, he had a facienda on the Amazon and a diversity of interests from oil to real estate, but he chose to honour his commitment to the Indians and it was 1916 before he returned to England. Resisting the efforts of the War Office to recruit him on the staff, he joined the Northumberland Yeomanry, fighting with a detached ferocity directed not at the enemy but at the blundering fools who had made the war. A year later he was invalided out with a shattered leg and a Distinguished Service Order and set about forming his own investment company. By now he had a retinue, an international reputation and offices in a dozen capitals, but Martha Hodge — as he returned at intervals to install into the house she resolutely refused to leave, first running water, then electricity, then a bathroom — continued to be troubled by the colour of his eyes.

Then, in the spring of 1922, he returned to Vienna.

1

Guy returned to the capital of a dismembered empire: a city impoverished by defeat, in the grip of inflation but still beautiful. The theatres were open, the concert halls were packed. The Viennese still danced, still sang. Sometimes, as the new republic struggled with the shortages and disruptions left by the war, they even ate.

Guy took a suite at Sachers, saw that his stenographer and chauffeur were suitably housed nearby and allowed himself a week of the swashbuckling entrepreneurism that was his hallmark, wresting the copper concessions in the Eisen Gebirge from an Armenian syndicate after a spectacular battle, and gleefully beating a South African tycoon to the lignite deposits near Graz. After which, considerably refreshed, he presented himself at the Treasury and plunged into the work which had brought him to Vienna.

It was work shrouded in secrecy, as vital and exacting as it was outwardly unspectacular. For Austria was seeking a huge loan from the League of Nations, seeing in this her only chance to stabilize her currency and set off along the road to recovery. It was to assist the new republic in presenting her case to the League that Guy had been sent out by the British government, who feared that a permanently weakened Austria would seek union with Germany. No one seeing him, day after day, courteous and patient, would have imagined how irksome he found the ponderous bureaucracy and time-wasting social functions in the stuffy, grandiose rooms of the Hofburg.

Then, on a fine Saturday at the end of March, Guy, obeying a summons from his young secretary David Tremayne, left the city, dismissed his chauffeur and turned his car southward towards the fortress known as Pfaffenstein. This is the most famous castle in Burgenland, an emblem for the whole of Austria — the embodiment for close on a thousand years of defensive power, aggression, grandeur and pride.

The position alone is breathtaking. At the head of a dark green lake whose glacial waters chill the blood even in midsummer, is a great pinnacle of rock rising skyward from the pines which cling to its base. To the east the crag, split from top to bottom by a fault in the rock, drops sheer to the Hungarian plain. To the north are the wooded slopes and jagged peaks of the Pfaffenstein mountains whose passes it dominates; to the west, sloping more gently, are the vineyards and orchards which merge in the far distance with the snow crown of the Alps.

On the summit of this gigantic eyrie, the last outcrop of the Pfaffenburg spur, the Franks built a fort at the time of Charlemagne, but even they were not the first. Two hundred years later, the Crusaders added a square of turreted towers, threw a drawbridge over the dizzying ravine to the east of the castle and rode out full panoplied against the infidel, bearing aloft the banner of the Pfaffensteins with its impaled griffin and crimson glove.

By the time Richard Coeur de Lion was brought there, pending his imprisonment at Durenstein, Burg Pfaffenstein was a thriving Romanesque citadel with a council chamber, a chapel and a village clinging humbly to the base of its crag. In subsequent centuries, as the Tartars invaded Hungary, the Hungarians invaded Austria and the Turks invaded both, its fame and importance increased as steadily as the power of its owners who became, by conquest and marriage, first counts, then margravines, then princes.

The rout of Sultan Mahomet’s troops after the second siege of Vienna, which banished the Turks for ever from Christendom, set in train a riot of new building as cannon bastions and barrier walls were blown up and the years of imperial splendour under the ever mightier Habsburgs were reflected in Pfaffenstein’s steadily increasing grandeur, opulence and pomp. Ignoring, but never quite managing to erase, the dungeons built deep into the rock, the torture chambers and oubliettes of the earlier fortress, the princes of Pfaffenstein built a palace along the southern front, the windows of its great state rooms sheer with the crag as it rose above the lake; blasted terraces out of the rock and threw pepper-pot turrets on to the flanking towers. A musical Pfaffenstein built a theatre, an Italianate one arcaded the courtyards, a prince of the Church enlarged the Romanesque chapel to form a soaring, gilded paean to the glory of God.

Larger than Hochosterwitz, more heavily fortified than the Esterhazy palace at Eisenstadt and far, far older than the castles that the poor mad Swan King Ludwig had built to the north in Bavaria, Burg Pfaffenstein, by the end of the nineteenth century, had become the subject of innumerable paintings and the inspiration of countless minor poets. The redoubtable Baedecker, when he arrived, gave it three stars.

To this castle, driving himself in his custom-built, tulip-wood Hispano-Suiza, came Guy Farne on a spring afternoon in 1922, with a view to purchase.

He came, as all who come from Vienna must, by the road which skirted the western side of the lake and as the fantastic, towering pile reared up before him, his wide mouth curved into an appreciative smile.

‘Yes,’ he said to the young man sitting beside him, ‘it will do. Definitely, it will do. You’ve done well, David.’

His secretary, David Tremayne, whose fair good looks and puppyish desire to please concealed a tireless efficiency, turned a relieved face to his employer. ‘I thought you’d like it, sir. I saw a few others but I don’t know… This one put them all in the shade.’

‘It certainly makes its own quiet statement,’ said Guy sardonically.

But as he switched off the engine and got out of the car, he momentarily caught his breath. Burg Pfaffenstein’s role as fortress, as refuge and as palace was evident in every stone. Now, in the still, green lake which mirrored with exquisite accuracy each tower and pinnacle and glistening spire, Guy saw it in another guise: as Valhalla or Venusberg — the castle as dream.

‘You’re certain the owners want to sell?’

‘Absolutely, sir. There are only the two old ladies left now and a great-niece in Vienna.’ And David fell silent, thinking with compassion of the proud, impoverished families he had visited in his search, all desperate to offer him their ducal Schloss or moated Wasserburg or hunting lodge.

Guy nodded, measuring the road which passed under the crag at the head of the lake and then vanished into the ravine.

‘Let’s see if we can make it without oxygen, then,’ he said and climbed back into the car.

But as Guy drove skilfully round the hair-raising bends that led up to the Burg, David was frowning. His instructions had been simple: to find an impressive and imposing castle (‘toffee-nosed’ was the word his employer had used, reverting to his origins) which the owners were willing to rent or preferably to sell.

Only why? This was something Guy Farne had not chosen to reveal to his otherwise trusted secretary, and the whole enterprise seemed totally out of keeping with what David knew of his employer’s tastes and inclinations. A millionaire he might be, and several times over, but his personal habits were spartan to a degree which caused deep pain to Morgan his chauffeur, to Miss Thisbe Purse, his stenographer, and at times to David himself. Farne’s indifference to comfort, his ability to go without food or sleep, his detestation of pomp were a byword, nor had he troubled to conceal his contempt for those post-war profiteers who conned the newly-poor out of their houses and possessions. True, his sojourn in Austria was likely to be of some duration and he needed a base — but why this gigantic castle? In Brazil, where other men of his wealth had bought palaces, he had lived in a simple if lovely facienda by the river, his only extravagance a steam yacht with which he explored the mazed waterways of the Amazon. In London he lived in an apartment in the Albany, in Paris in a roof-top flat in the Ile St Louis which but for the glory of its plumbing might have belonged to any Left Bank painter or poet. Only on movement — elegant boats, fleet cars and (his latest acquisition) a small bi-plane — did Farne habitually spend the awe-inspiring sums which betrayed his stupendous wealth.

They had negotiated that last hairpin bend, crossed the drawbridge, been sneered at by the griffins on the gatehouse arch and now drew up in a vast and silent courtyard.