The Scarlet Impostor was described by a contemporary critic as ‘the first great spy story of the war’ – World War II, that is. Actually it didn’t have much competition, since it was published in January 1940. With astonishing, but not uncharacteristic, industry Dennis Wheatley had written the entire book – at 172,000 words, twice the length of most thrillers – during the first few weeks of the war, between the 6th of September and the 19th of October. Bound copies were ready by Christmas; publishers too were quicker in those days.

Wheatley considered it one of his best books, and he was right. Taken together with its immediate successors Faked Passports and The Black Baroness, which were produced with equal speed and which cover, respectively, the Russo-Finnish War and the Nazi sweep across Europe, it demonstrates the full flowering of a genre which, from the beginning, Dennis Wheatley had made peculiarly his own – the toughly masculine but romantic thriller set in real places and rooted in major political events of the day, both the places and the politics being described in substantial and authentic detail. Later, when he came to write historical novels such as The Prisoner in the Mask, about the Dreyfus affair, and the Roger Brook series about the Napoleonic Wars, he simply transferred this technique to an earlier, carefully researched epoch. The fruits of his research were sometimes undigested, so that Roger Brook, returning to Paris, was apt to say: ‘Tallyrand, tell me what’s been happening’. After which would follow several pages drawn from books about the period. G.A. Henty used to promise his schoolboy readers that if they absorbed the history in his novels, it would be enough to get them through their exams. Wheatley could have made the same pledge; he prided himself that all his books were instructive as well as exciting.

Today’s reader, accustomed to the works of Ian Fleming and John le Carré, may not find Dennis Wheatley’s spy stories very sophisticated. But they seemed so at the time. He was the first to give shops, clubs, hotels and branded goods their proper names. The stories are not realistic in the crude modern sense, but they imply a good deal of worldly knowledge. They are never gratuitously unpleasant, but they contain plenty of sex and violence. Their morality (which was Wheatley’s own) is tolerant of the sins of the flesh, but unfailingly patriotic and chivalrous.

By all means read The Scarlet Impostor simply as a thriller. Although Wheatley was no great literary stylist, he had what Raymond Chandler said was the essential writer’s gift of ‘making each page throw the hook for the next’. But it is important, from other points of view, to remember when the book was written. Its attitude to the war, its observation of the way things looked in the autumn of 1939 and its speculation about how the conflict might develop, come to us now, half a century later, through clear glass, undistorted by hindsight or the embellishments of memory.

Conan Doyle was always irritated that his excellent historical novels attracted less attention than the Sherlock Holmes tales, which he regarded as mere pot-boilers: but time has had a paradoxical effect. The Sherlock Holmes stories, with their unforgettable picture of fog-bound Victorian London, have become the most historically vivid of all Doyle’s work. A similar fate has perhaps already befallen Dennis Wheatley. In the Roger Brook series he passes on, mildly decorated, the burden of his reading: but in The Scarlet Impostor and its sequels he whips us back, directly, into the ominous ‘phoney war’ of 1939 and the storm which broke in the spring of 1940.

These books were, in a sense, the beginning of Dennis Wheatley’s war-work. They were intended as entertainment to lighten dark days but are full of zeal for Britain’s cause. Having served in France during the First World War, he would have liked to get back into uniform (‘the proper dress for any gentleman when Britain is at war’) but recognised that, at the age of forty-two, the best he could hope for was probably a civilian job. Joan, his second wife, and two of his stepchildren were soon working, because of an earlier connection, for MI5: but Wheatley himself was offered nothing. ‘Go on writing,’ he was told. The Ministry of Information also rejected him; which was just as well. He would not have liked that prissy organisation, nor would it have liked him.

Eventually, as the little ships were bringing the British Expeditionary Force home from Dunkirk, he was invited, at Joan’s suggestion, to compose for private circulation at a high level some imaginative papers about the tactics and devices with which a German invasion of Britain might be resisted.

One thing led to another, and by the autumn of 1941 he had written over half-a-million words for the Joint Planning Staff, as well as three more novels. Then at last he was offered a uniform. Commissioned, strangely, into the RAF, he joined a new section of the Chiefs of Staff Organisation, working in the offices of the War Cabinet. For the next three years – at an age when, as he said, he might have been put to guarding a reservoir – he was engaged in the fascinating task of Deception Planning, which culminated in the various schemes to mislead the enemy about where and when the D-Day landings would take place.

After the war he completed the cycle of tales which The Scarlet Impostor began. V for Vengeance, about Occupied France, which is the weakest of the series, he had already finished before being immersed in official work. The rest – Come into My Parlour, Traitor’s Gate and finally They Used Dark Forces, which takes the hero, Gregory Sallust, to Hitler’s bunker in Berlin as the Third Reich was overwhelmed – were written well after the periods they describe. They have, therefore, both the advantages and the disadvantages of hindsight. They lack The Scarlet Impostor’s immediacy, but they do cover the whole remaining history of the Second World War.

Gregory Sallust, however, had both an earlier and a later existence. He first appeared, during the 1930s, in a fantasy about revolution in England called Black August. Then he featured, more plausibly, in Contraband, a pre-War thriller about the smuggling of Communist agitators into Britain. Not until The Scarlet Impostor, where he meets his great love and future wife, Erika von Epp, did he really become his own man. The third phase of Gregory’s adventures proved, happily, no anti-climax. The Island Where Time Stands Still and The Witch of the South Seas, in which he loses Erika and, long afterwards, finds her again, are ripe examples of the late Wheatley style, bustling narratives with exotic backgrounds.

Gregory Sallust kept returning to the stage at the request of many readers. The Scarlet Impostor shows, as well as any book in the series, why they wanted him. It heralded his finest hour – and Dennis Wheatley’s.

Anthony Lejeune, 1988