Split by an immense roar, the early morning silence over the lagoon shattered abruptly, and a tremendous blare of noise battered past the windows of the hotel suite. With an effort Kerans pulled his reluctant body from his bed and stumbled across the books scattered on the floor. He kicked back the mesh door on to the balcony in time to see a huge white-hulled hydroplane speed by around the lagoon, its two long stepped planes cleaving perfect slices of glittering spray. As the heavy wash slapped against the wall of the hotel, breaking up the colonies of water spiders and disturbing the bats nesting among the rotting logs, he caught a glimpse of a tall, broad-shouldered man in the cockpit, wearing a white helmet and jerkin, standing upright at the controls.

He drove the hydroplane with an easy nonchalant swagger, accelerating the two powerful propellor turbines mounted in front of him as the craft hit the broad swells across the lagoon, so that it plunged and dived like a power-boat wrestling through giant rollers, throwing up gales of rainbowing spray. The man rolled with the surging motion of the craft, his long legs supple and relaxed, like a charioteer completely in command of a spirited team.

Hidden by the calamites which now spilled across the balcony-the effort of cutting them back had long seemed pointless-Kerans watched him unobserved. As the craft sped by on its second circuit, Kerans had a glimpse of a rakish profile, bright eyes and teeth, an expression of exhilarated conquest.

The silver studs of a cartridge belt flashed around his waist, and when he reached the far side of the lagoon there was a series of short explosions. Signal shells burst over the water into ragged red umbrellas, the fragments spitting down across the shore.

In a final lunge of energy, its engines screaming, the hydroplane swerved out of the lagoon and gunned away down the canal to the next lagoon, its wash thrashing at the foliage. Kerans gripped the balcony rail, watching the disturbed restless water of the lagoon trying to re-settle itself, the giant cryptograms and scale trees along the shore tossed and flurried by the still surging air. A thin pall of red vapour drifted away to the north, fading with the diminishing sounds of the hydroplane. The violent irruption of noise and energy, and the arrival of this strange white-suited figure, momentarily disconcerted Kerans, jerking him roughly from his lassitude and torpor.

In the six weeks since Riggs' departure he had lived almost alone in his penthouse suite at the hotel, immersing himself more and more deeply in the silent world of the surrounding jungle. The continued increase in temperature-the thermo-alarm on the balcony now registered a noon high of one hundred and thirty degrees-and the enervating humidity made it almost impossible to leave the hotel after ten o'clock in the morning; the lagoons and the jungle were filled with fire until four o'clock, by then he was usually too tired to do anything but return to bed.

All day he sat by the shuttered windows of the suite, listening from the shadows to the shifting movement of the mesh cage, as it expanded and contracted in the heat. Already many of the buildings around the lagoon had disappeared beneath the proliferating vegetation; huge club mosses and calamites blotted out the white rectangular faces, shading the lizards in their window lairs.

Beyond the lagoon the endless tides of silt had begun to accumulate in enormous glittering banks, here and there over-topping the shoreline, like the immense tippings of some distant gold-mine. The light drummed against his brain, bathing the submerged levels below his consciousness, carrying him downwards into warm pellucid depths where the nominal realities of time and space ceased to exist. Guided by his dreams, he was moving backwards through the emergent past, through a succession of ever stranger landscapes, centred upon the lagoon, each of which, as Bodkin had said, seemed to represent one of his own spinal levels. At times the circle of water was spectral and vibrant, at others slack and murky, the shore apparently formed of shale, like the dull metallic skin of a reptile. Yet again the soft beaches would glow invitingly with a glossy carmine sheen, the sky warm and limpid, the emptiness of the long stretches of sand total and absolute, filling him with an exquisite and tender anguish.

He longed for this descent through archaeopsychic time to reach its conclusion, repressing the knowledge that when it did the external world around him would have become alien and unbearable.

Sometimes he restlessly made a few entries in his botanical diary about the new plant forms, and during the first weeks called several times on Dr. Bodkin and Beatrice Dahl. But both were increasingly preoccupied with their own descents through total time. Bodkin bad become lost in his private reverie, punting aimlessly around the narrow creeks in search for the submerged world of his childhood. Once Kerans came across him resting on an oar in the stern of his small metal scow and gazing vacantly at the unyielding buildings around him. He had stared straight through Kerans, failing to acknowledge his call.

However, with Beatrice, despite their superficial estrangement, there was an intact underlying union, a tacit awareness of their symbolic roles.

More signal shells burst over the distal lagoon, containing the station and Beatrice's apartment house, and Kerans shielded his eyes as the bright fire-balls studded the sky. A few seconds later, several miles away among the silt banks to the south, there was a series of answering bursts, faint puffs that soon dispersed.

So the stranger driving the hydroplane was not alone. At the prospect of this imminent invasion Kerans pulled himself together. The distance separating the answering signals was wide enough to indicate that there was more than one group, and that the hydroplane was merely a scout vehicle.

Sealing the mesh door behind him, he stepped back into the suite, pulling his jacket off the chair. Out of habit he went into the bathroom and stood in front of the mirror, absently feeling the week-old stubble on his face. The hair was white as pearl, and with his ebony tan and introspective eyes gave him the appearance of a refined beachcomber. A bucket-full of dingy water had leaked in from the wrecked still on the roof, and he scooped some out and splashed his face, a token toilet performed, as far as he could see, solely out of habit.

Using the metal-tipped boathook to drive away two small iguanas idling on the jetty, he slid the catamaran into the water and cast off, the little outboard carrying him steadily through the sluggish swells. Huge clumps of algae stirred below the craft, and stick-beetle and water spider raced around its prows. It was a few minutes after seven o'clock, and the temperature was only eighty degrees, comparatively cool and pleasant, the air free of the enormous clouds of mosquito which would later be roused from their nests by the heat.

As he navigated the hundred-yard-long creek leading into the southern lagoon, more signal rockets were exploding overhead, and he could hear the hydroplane zooming to and fro, occasionally glimpse the white-suited figure at its controls as it flashed past. Kerans cut the outboard at the entrance to the lagoon and glided quietly through the overhanging fern fronds, watching for water snakes disturbed from the branches by the surging wash.

Twenty-five yards along the shore he berthed the catamaran among the horse-tails growing on the shelving roof of a department store, waded up the sloping concrete to a fire escape on the side of the adjacent building. He climbed the five storeys to the flat rooftop and lay down behind a low pediment, glancing up at the nearby bulk of Beatrice's apartment house.

The hydroplane was circling noisily by an inlet on the far side of the lagoon, the driver plunging it backwards and forwards like a horseman reining his steed. More flares were going up, some only a quarter of a mile away. As he watched Kerans noticed a low but mounting roar, a harsh animal sound not unlike that emitted by the iguanas. It drew nearer, mingled with the drone of engines, followed by the noise of vegetation being torn and buffeted. Sure enough, along the course followed by the inlet, the huge fern trees and calamites were flung down one after the other, their branches waving as they fell like vanquished standards. The whole jungle was being torn apart. Droves of bats erupted into the air and scattered frantically across the lagoon, their screeching masked by the accelerating turbines of the hydroplane and the exploding star-shells.

Abruptly, the water in the mouth of the inlet rose several feet into the air, what seemed to be an enormous log-jam crushed down it, tearing the vegetation away, and burst out into the lagoon. A miniature niagara of foaming water cascaded outwards, impelled by the pressure of the tidal bore behind it, on which rode several square black-hulled craft similar to Colonel Riggs' cutter, paint peeling from the giant dragon eyes and teeth slashed across their bows. Manned by a dozen dusky-skinned figures in white shorts and singlets, the scows jockeyed out towards the centre of the lagoon, the last of the star-shells still going up from their decks in the general melee and excitement.

Half-deafened by the noise, Kerans stared down at the vast swarm of long brown forms swimming powerfully through the seething water, their massive tails lashing the foam. By far the largest alligators he had seen, many of them over twenty-five feet long, they jostled together ferociously as they fought their way into the clear water, churning in a pack around the now stationary hydroplane. The white-suited man was standing in the open hatchway, hands on hips, gazing exultantly at this reptilian brood. He waved lazily at the crews of the three scows, then gestured in a wide circle at the lagoon, indicating that they would anchor there.

As his negro lieutenants re-started their engines and drifted off towards the bank, he surveyed the surrounding buildings with a critical eye, his strong face raised almost jauntily to one side. The alligators congregated like hounds around their master, the wheeling cries of the dense cloud of sentinel birds overhead, nile plover and stone curlew, piercing the morning air. More and more of the alligators joined the pack, cruising shoulder to shoulder in a clockwise spiral, until at least two thousand were present, a massive group incarnation of reptilian evil.

With a shout, the pilot swung back to his controls, the two thousand snouts lifting in recognition. The propellors kicked into life and lifted the hydroplane forward across the water. Its sharp planes ploughing straight across the hapless creatures in their path, it drove away towards the communicating creek into the next lagoon, the great mass of alligators surging along behind it. A few detached themselves and cruised off in pairs around the lagoon, ferreting among the submerged windows and driving off the iguanas who had come out to watch. Others glided among the buildings and took up their positions on the barely covered rooftops. Behind them, in the centre of the lagoon, the beaten water churned uneasily, occasionally throwing up the snow-white belly of a dead alligator crushed by the hydroplane.