Despite the almost static light, fixed at this unending dusk, the drained bed of the river seemed to flow with colours. As the sand spilled from the banks, uncovering. the veins of quartz and the concrete caissons of the embankment, the evening would flare briefly, illuminated from within like a lava sea. Beyond the dunes the spires of old water towers and the half-completed apartment blocks near the Roman ruins at Leptis Magna emerged from the darkness. To the south, as Halliday followed the winding course of the river, the darkness gave way to the deep indigo tracts of the irrigation project, the lines of canals forming an exquisite bonelike gridwork.

This continuous transformation, whose colours were as strange as the bizarre paintings hung from the walls of his suite, seemed to Halliday to reveal the hidden perspectives of the landscape, and of the time whose hands were almost frozen on the dozen clocks standing on the mantelpiece and tables. The clocks, set to the imperceptible time of the forever day, he had brought with him to North Africa in the hope that here, in the psychic zero of the desert, they might somehow spring to life. The dead clocks that stared down from the municipal towers and hotels of the deserted towns were the unique flora of the desert, the unused keys that would turn the way into his dreams.

With this hope, three months earlier he had come to Columbine Sept Heures. The suffix, attached to the names of all cities and towns — there were London 6 p.m. and Saigon Midnight — indicated their positions on the Earth’s almost stationary perimeter, the time of the endless day where the no longer rotating planet had marooned them. For five years Halliday had been living in the international settlement at Trondheim in Norway, a zone of eternal snow and ice, of pine forests whose arbours, fed by the unsetting sun, rose even higher around the fringes of the towns, shutting them into their own isolation. This world of Nordic gloom had exposed all Halliday’s latent difficulties with time and with his dreams. The difficulty of sleeping, even in a darkened room, disturbed everyone — there was the sense of time wasted and yet time unpassed as the sun hung stationary in the sky — but Halliday in particular found himself obsessed by his broken dreams. Time and again he would wake with an image before his eyes of the moonlit squares and classical faades of an ancient Mediterranean town, and of a woman who walked through colonnades in a world without shadows.

This warm night world he could find only by moving south. Two hundred miles to the east of Trondheim the dusk line was a corridor of freezing wind and ice, stretching on into the Russian steppe, where abandoned cities lay under the glaciers like closed jewels. By contrast, in Africa the night air was still warm. On the west of the dusk line was the boiling desert of the Sahara, the sand seas fused into lakes of glass, but along the narrow band of the terminator a few people lived in the old tourist towns.

It was here, at Columbine Sept Heures, an abandoned town beside the drained river five miles from Leptis Magna, that he first saw Gabrielle Szabo walking towards him as if out of his dreams. Here, too, he met Leonora Sully, the fey unconcerned painter of bizarre fantasies, and Dr Richard Mallory, who tried to help Halliday and bring back his dreams to him.

Why Leonora was at Columbine Sept Heures Halliday could understand, but sometimes he suspected that Dr Mallory’s motives were as ambiguous as his own. The tall aloof physician, eyes forever hidden behind the dark glasses that seemed to emphasize his closed inner life, spent most of his time sitting in the white-domed auditorium of the School of Fine Arts, playing through the Bartok and Webern quartets left behind in the albums.

This music was the first sound Halliday heard when he arrived at the desert town. In the abandoned car park near the quay at Tripoli he found a new Peugeot left behind by a French refinery technician and set off south along the seven o’clock line, passing through the dusty towns and the half-buried silver skeletons of the refineries near the drained river. To the west the desert burned in a haze of gold under the unmoving sun. Rippled by the thermal waves, the metal vanes of the waterwheels by the empty irrigation systems seemed to revolve in the hot air, swerving toward him.

To the east the margins of the river were etched against the dark horizon, the ridges of exposed limestone like the forestage of the twilight world. Halliday turned toward the river, the light fading as he moved eastward, and followed the old metal road that ran near the bank. The centre of the channel, where white rocks jutted from the drifts of pebbles, lay like the spine of an ancient saurian.

A few miles from the coast he found Columbine Sept Heures. Four tourist hotels, their curtain walls like dead mirrors, stood among the dunes that drifted through the streets and overran the chalets and swimming pools near the Fine Arts School. The road disappeared from sight outside the Oasis Hotel. Halliday left the car and walked up the steps to the dust-filled lobby. The sand lay in lacelike patterns across the tiled floor, silting against the pastel-coloured elevator doors and the dead palms by the restaurant.

Halliday walked up the stairway to the mezzanine, and stood by the cracked plateglass window beyond the tables. Already half submerged by the sand, what remained of the town seemed displaced by the fractured glass into another set of dimensions, as if space itself were compensating for the landscape’s loss of time by forcing itself into this bizarre warp.

Already decided that he would stay in the hotel, Halliday went out to search for water and whatever food supplies had been left behind. The streets were deserted, choked with the sand advancing toward the drained river. At intervals the clouded windows of a Citro’n or Peugeot emerged from the dunes. Stepping along their roofs, Halliday entered the drive of the Fine Arts School. Against the cerise pall of the dusk, the angular building rose into the air like a white bird.

In the students’ gallery hung the fading reproductions of a dozen schools of painting, for the most part images of worlds without meaning. However, grouped together in a small alcove Halliday found the surrealists Delvaux, Chirico and Ernst. These strange landscapes, inspired by dreams that his own could no longer echo, filled Halliday with a profound sense of nostalgia. One above all, Delvaux’s The Echo’, which depicted a naked Junoesque woman walking among immaculate ruins under a midnight sky, reminded him of his own recurrent fantasy. The infinite longing contained in the picture, the synthetic time created by the receding images of the woman, belonged to the landscape of his unseen night. Halliday found an old portfolio on the floor below one of the trestles and began to strip the paintings from the walls.

As he walked across the roof to the outside stairway above the auditorium music was playing below him. Halliday searched the faces of the empty hotels, whose curtain walls lifted into the sunset air. Beyond the Fine Arts School the chalets of the students’ quarter were grouped around two drained swimming pools.

Reaching the auditorium, he peered through the glass doors across the rows of empty seats. In the centre of the front row a man in a white suit and sunglasses was sitting with his back to Halliday. Whether he was actually listening to the music Halliday could not tell, but when the record ended three or four minutes later he stood up and climbed onto the stage. He switched off the stereogram and then strolled over to Halliday, his high face with its slightly inquisitorial look hidden behind the dark glasses.

‘I’m Mallory — Dr Mallory.’ He held out a strong but oblique hand. Are you staying here?’

The question seemed to contain a complete understanding of Halliday’s motives. Putting down his portfolio, Halliday introduced himself. ‘I’m at the Oasis. I arrived this evening.’