Perhaps we shall soon come to somewhere; perhaps we shall even meet Rimbaud, strangely sensed as one who, wherever you turn up, has just left the room.Certain of Nicholl’s tricks do not feel right. The on-the-road Bob Dylan sub-theme is pure hippy sentimentality. The switches from past to present tense in historical passages is bogus originality. The present tense in biographical work always comes across as mannered, though not in autobiography. In autobiography the present tense brings one closer to the subject, whereas in biography it takes one further away. So the present is obviously less grating when Nicholl employs it to recount his own recent journeys in Rimbaud’s footsteps.Yet Nicholl keeps himself quite as much of a ghost as Rimbaud, in what one may call the peeping-Tom school of travel writing (Bruce Chatwin and Colin Thubron are the recent masters).

The author says “Just go about your affairs as though I weren’t here”, which produces endless scene-setting and no adventure. Nicholl gives us a superb description of the arrival of evening in Djibouti – an evening on which nothing whatsoever happens.The avoidance of emotional contact is very English and maybe even appropriate. In Africa, Rimbaud sought to turn himself into a stoical, abstracted Englishman. Previously he’d been outrageously the Parisian artist, extravagantly self- aware and expressive, pushing poetry off all sorts of cliffs.Eventually one adjusts to Nicholl’s oscillation of unrealised possibilities and shifts of perspective, even when the background swallows up the foreground. Ratzel turned territorial expansion into the primary sign of a race’s vitality He also pressed for the creation of a German empire.

But it was not until 1904 that Germany got round to exterminating the Herero of South West Africa, and there was little distant Lebensraum left to conquer So the logic of extermination was brought home to Europe. Hitler grew up with the belief that imperialism was “biologically necessary”, and entailed the “destruction of the lower races”. He was convinced of the need for “living space”.The “Lebensraum” idea was first promoted by the German zoologist and geographer Friedrich Ratzel, who in 1891 insisted that races of “inferior culture” died out because Europeans destroyed them in order to take their land. But the great evolutionist still foresaw a time when the “savage races” would be exterminated by their civilised superiors. From then on, “it became accepted to shrug your shoulders at genocide”.Having exposed the ideas that justified European imperialism, and the extinction of native peoples, Lindqvist argues that the Nazi holocaust had its roots in 19th-century European thought. But others are more philosophical, like the idea of extinction, which Lindqvist traces back to Cuvier, who pointed in the 18th century to the extinction of prehistoric animals.

This was elaborated in 1850 by Robert Knox, a race theorist who turned extermination into a fact of nature, arguing that “the dark races” were incapable of becoming civilised, and must instead “go under” to the Saxons.Charles Darwin loathed the brutality he saw on his travels, including the systematic extermination of Indians in the Argentine. There really was a man, Captain Rom, who decorated the gardens of his house at Stanley Falls with the severed heads of 21 Africans killed during a punitive missions. He reviews the necessary technological innovations from Mr Dunlop’s invention of the bicycle inner tube, which helped to trigger demand for rubber, to the weapons that made safe slaughter possible – gunboats, rifles and the “dum-dum” bullets used for stopping “savages” but banned from European wars.Some elements of Conrad’s story were lifted straight from outrageous reality. He traces Conrad’s interest in the imperial expeditions of that time: Stanley’s triumphant return in 1889 from a three-year expedition, actually a farcical and disastrous affair, to rescue Emin Pasha from “dervishes” in Sudan. As for the 100 floppy disks in his bag, they contain what he takes to be “the core of European thought”, excavated over countless days in the libraries of Europe.His title is quoted from Joseph Conrad’s Heart of Darkness, a novella written in the last years of the 19th century, which tells of a voyage upriver into the African continent in search of Kurtz, who has vanished into the savagery of colonialism. Lindqvist first read this book as a young man just after the Second World War, when it appeared to foreshadow the Nazi holocaust.The connection between 19th-century imp- erialism and 20th-century fascism remains his preoccupation as he travels through the parched emptiness of the desert: noting tiny incidents on the sites of past atrocities; collecting the vivid dreams that still disturb the passing European, and pressing them between his pages, rather as if they were exotic desert flowers.Conrad’s story was written at the height of British imperialism, and Lindqvist establishes it as a thoroughgoing condemnation of colonial violence. Presenting himself as a resolutely unheroic figure, he draws on many visits to Africa over decades.