Buchan's final steps

As she took down his dictation in his bedroom at Rideau Hall, the governor-general's residence in Ottawa, she noticed how he twisted and turned to find some flesh to support his emaciated frame. One of the model lives of the belated British Empire was coming to an end in the cold Canadian sunshine. Buchan was 64, had written 97 books - including a thriller a year since 1922 - had just signed Canada's declaration of war and sent three sons off to fight Germans, and in a few weeks would be dead.

Buchan was a good viceroy: the best of the British, as the Canadians liked to say. Though he had been in pain from duodenal ulcers since 1916 he soldiered on, spinning out a couple of poached eggs through his long official dinners lest the footmen see His Excellency had finished and whip all the plates away. Confined to stifling ceremonial and good works, warned off politics and Canada's foreign relations by Mackenzie King, the Canadian prime minister, he made incessant journeys all over Canada and came to know and admire the country as no governor-general before him.

With his writer's curiosity, Buchan did not feign interest in the pedigree bulls, milk-condensing plants, centenarians, dinosaur remains, juniper-root carvings, native Canadian dances, veterans of old wars, historic occasions and military reviews that were the stuff of Governor-Generals' tours at that time. For John Buchan, Canada - and, to an extent, the United States - were "Scotland on an extended scale", the land in which he has been born in 1875, the son of a Church of Scotland minister and a 17-year-old hill-farmer's daughter and to which he would not now be returning. In the intervals of his duties, he dictated to Mrs Killick a life of the first Roman emperor, Augustus (1937); The Long Traverse (1941); a book of Canadian history for children; an autobiography, Memory Hold-the-Door (1940); and the novel Sick Heart River (1941).

On 20 July, 1937, he set off on the most ambitious of his Canadian journeys and one that was to shape his last years and his last book. It was a tour of the north, the direction you take in his fiction if you have business with death. Leaving Edmonton by train, at the railhead at Waterways the governor-general's party transferred to a Hudson's Bay Company stern-wheeler for the journey north down the Athabasca River. Soon after they set off, a float plane came down beside them and out stepped, onto the pontoon, the photographer Margaret Bourke-White, on assignment to cover the trip for Life magazine and dressed amid the viceregal plumes in trousers and a tartan shirt. Buchan liked her very much, and let her photograph him in a sort of intense mental solitude, sitting quite still and alone at the back of the crowded smoking-room of the Athabasca River playing patience, or out on the deck amid the gear, indexing his Augustus. "A long narrow table had been contrived for him with a couple of planks and there he sat with the fluttering little white paper markers of his index all over the place," Bourke-White later wrote. "Our cargo almost swallowed him up. His spare form was all but lost in the midst of the pig crates, the cage of chickens, the tractor, the assortment of agricultural implements that surrounded him. Several times I tiptoed up and photographed his expressive back, but I never interrupted him while he was working." At Fort Chipewyan, they passed into the Slave River. After a short portage around the rapids, they transferred to another stern-wheeler, the Distributor, for the thousand-mile journey to the Arctic Ocean. At the Great Slave Lake, they joined the Mackenzie River, stopped at forts and trading posts, met Roman Catholic priests and nuns, traders, trappers and Hudson's Bay officers, saw on the left the dark mass of the Mackenzie Mountains and came out at the vast delta described in a sort of elemental horror in Sick Heart River. At Aklavik, Buchan opened a hospital, then flew over the Great Bear Lake to Coronation Gulf, called on an Inuit family that had brought a neat schooner through the ice of the western Arctic. Returning via Alberta and British Columbia, he flew over the coastal range and saw below him a place he had half seen, half dreamt of since his childhood in the Scottish Borders and his youth in South Africa: a cup in the hills, "with a lake, a half-moon of wild meadow, and behind it another half-moon of forest".

Like many invalids, Buchan pressed out every drop from his experiences. A yacht cruise in the Aegean in the spring of 1910 had been good for several short stories and two novels, Greenmantle (1916) and The Dancing Floor (1926).

All that he had seen in the north - priests, trappers, an Inuit schooner anchored by a sandbank, the Mackenzie Mountains, the sanctuary in the hills - passed into Sick Heart River. What Buchan did not have from his northern tour was an Arctic winter but that, with his usual economy, he supplied from travellers' accounts such as those of the Toronto insurance broker George M Mitchell in the Yukon (The Golden Grindstone, 1935) and conversations with eldest son, Johnnie, who had spent winter 1938-9 as under-post-manager for the Hudson's Bay Company at Cape Dorset in Baffin Land. It is one of those mysteries of writing that some of the most powerful effects in Sick Heart River - indeed, in all of Buchan's works - are at second hand:

"The cold was more intense than anything he had ever imagined. Under its stress trees cracked with a sound like machine-guns. The big morning fire made only a narrow circle of heat. If for a second he turned his face from it the air stung his eyelids as if with an infinity of harsh particles. To draw breath rasped the throat. The sky was milk-pale, the sun a mere ghostly disc, and it seemed to Leithen as if everything - sun, trees, mountains - were red-rimmed. There was no shadow anywhere, no depth or softness. The world was hard, glassy, metallic; all of it except the fantasmal, cotton-wool skies."

If Buchan had his setting (the North) and his theme (dying), he needed a character. Of the personnel of his thrillers, Richard Hannay was too hale, Archie Roylance too boisterous, Lord Lamancha too shadowy, Dickson McCunn too commercial, Sandy Clanroyden too heroic. That left the lawyer, Sir Edward Leithen, devised 30 years previously - for the short story "Space" (1912) - when Buchan was himself trying to make his way at the London Bar. Leithen is "a man of good common-place intelligence" who has made a solid success in a legal speciality, financial law, where Buchan himself had left no mark, a "philistine lawyer" who nevertheless has an acute flair for the uncanny, a sort of second sight. A bachelor, Leithen will nevertheless go to the ends of the earth for a virtuous young wife, Lady Pamela Brune, in The Gap in the Curtain (1932) or Felicity Galliard in Sick Heart River. (Buchan's titles are the best in English after Shakespeare's, but the names of his characters are another matter.)

Above all, Buchan gave Leithen his illnesses, not now the battle-shocked taedium vitae of John Macnab (1925) or the neurotic overwork of The Gap in the Curtain (1932), but agonising pain and permanent fatigue. Leithen had come out of the Great War in pieces, "after the Boche made quite a good effort in the way of a gas attack". The scars on his lungs had become advanced tuberculosis, and Sick Heart River opens in the Harley Street consulting rooms of an eminent doctor who pronounces that Leithen has scarcely a year to live. Under mutual sentence of death, both author and character permit themselves that introspection that so struck Lillian Killick. In a sort of daze, Leithen unwinds all his ties to the Buchanite London of Parliament, Inns of Court, the parks, the Albany, the clubs. Like Charles Ottery in The Gap in the Curtain, who views his own death in the columns of the Times a year on, Leithen is at first paralysed by his impending extinction. With an effort of pure will, he determines to "die standing". Fortunately, his old friend Blenkiron (Greenmantle) turns up in London and asks his help in locating his niece's husband, Francis Galliard, a French-Canadian banker in New York who has walked out on his wife and partners and vanished into the North. Galliard is, in a lapse into Buchan's old manner, "too valuable a man" for the United States "to lose".

Leithen's quest begins in New York, moves on to Quebec, then by air over the Barrens to the shores of the Arctic Ocean and then, on foot, into those dark and mysterious mountains that Buchan had watched from the deck of the Distributor, following the track of Galliard and his half-Scots, half-native guide, Lew Frizel. After a nightmare ascent that takes Leithen to the limit of his strength and some distance beyond, he and Frizel's brother Johnny find Galliard. Frizel himself has abandoned his client and set off in a sort of blind fury to the Sick Heart River - Rivire du Coeur Malade - an all but inaccessible canyon as enchanted and deathly as its name. There Leithen manages to bring Frizel to his senses and bring him out with the taint of death on them both. On the descent, Leithen miraculously recoups his strength and dares to dream of a British old age in Scotland and the Cotswolds. Hunting to survive, rather than from boredom as in the other books, Leithen drops a caribou stag at 350 yards. ("Poorish head," says Galliard, as if stuck in John Macnab.) As the story moves without flagging towards its close, Leithen regains not only his philosophy but his sovereignty over the disposal of his life. He dies standing.

As always, Buchan's fiction is laced with propaganda. The parade of Canadian races - the CanuckGalliard, the Roman Catholic brothers, the native Canadians, the Mtis Frizels - are a call to unity under the shadow of war, as is the transparent flattery of the US. The Frizels, who have already fought one war in France, are bursting to enlist again in a conflict of whose causes they know nothing and wish to know nothing. ("Seems it's them darned Germans again. And Britain's in it. Likewise Canada.") Buchan loathed war, but knew that this one had to be fought.

Yet for all of this "official" character, nowhere else in Buchan's fiction are his conventional attitudes so weak and his heart so strong. He was a practical man. Unlike his equal in sickness and superior in craft, Robert Louis Stevenson, he managed to complete his masterpiece and then die. "In judging another man's life," wrote Michel de Montaigne, "I always inquire how he behaved at the last."

On 6 February 1940, while shaving in the tiled bathroom at Rideau Hall, Buchan had a cerebral thrombosis, fell, and hit the back of his head. Transferred to the Neurological Institute in Montreal, he had several operations but never regained consciousness and died on 11 February 1940. The world Buchan knew and, for the most part loved, was extinguished in the war. For some reason known only to the gods of Literature, the books he wrote are still read.

John Buchan: A life in 97 books

• Perth-born John Buchan (1875-1940) was appointed secretary to the British high commissioner in South Africa in 1901 and his first adventure novel, Prester John, was set there. He became a Scottish Unionist MP in 1927 and Canada's governor-general in 1935.

• Of his 97 books, The Thirty-Nine Steps, written in 1915, remains the best known. It has been adapted three times for film - by Alfred Hitchcock in 1935; in 1959, and in 1978, with Robert Powell as Richard Hannay.

• Buchan's potboilers have proved formative for many writers. Those citing him as a significant part of their literary diet include Alexander McCall Smith, Henry Porter, Michael Dibdin and Frederick Forsyth. There's a much-repeated, and possibly even true, story that when the young Ian Rankin was worried about being cast as a genre writer, his mentor Allan Massie asked, "Who would want to be a dry academic writer when they could be John Buchan?"