Crouched down in a small office two floors above the barrage, Kerans listened to the music playing amid the lights on the top deck of the depot ship. Strangman's party was still in full swing. Propelled by two junior members of the crew, the big paddles rotated slowly, their blades dividing the coloured spot lights and swinging them up into the sky. Seen from above, the white awnings resembled the marquee of a fairground, a brilliant focus of noise and festivity in the darkened square.

As a concession to Strangman, Riggs had joined him at this farewell party. A bargain had been struck between the two leaders: earlier the machine-gun had been withdrawn and the lower level placed out of bounds to the Colonel's men, while Strangman agreed to remain within the perimeter of the lagoon until Riggs had left. All day Strangman and his pack had roved the streets, and the random sounds of looting and firing echoed to and fro. Even now, as the last guests, the Colonel and Beatrice Dahl, left the party and climbed the fire escape to the testing station, fighting had broken out on deck and bottles were being hurled down into the square.

Kerans had put in a token appearance at the party, keeping well away from Strangman, who made little attempt to talk to him. At one point, between cabaret turns, he had swept past Kerans, deliberately brushing his elbow, and toasted him with his goblet.

"I hope you're not too bored, Doctor. You look tired." He turned a wicked smile on Riggs, who was sitting erectly on a tasselled silk cushion with a circumspect expression on his face like a district commissioner at a pasha's court. "The parties Dr. Kerans and I are used to are very different affairs, Colonel. They _really_ go with a bang."

"So I believe, Strangman," Riggs replied mildly, but Kerans turned away, unable, like Beatrice, to mask his revulsion for Strangman. She was looking over her shoulder across the square, a small frown for a moment hiding the mood of torpor and self-immersion to which she was again returning.

Watching Strangman from the distance as he applauded the next cabaret turn, Kerans wondered whether in some way he had passed his peak, and was beginning to disintegrate. He now looked merely loathsome, like a decaying vampire glutted with evil and horror. The sometime charm had vanished, in its place a predatory gleam. As soon as he could, Kerans feigned a mild attack of malaria, and made his way out into the darkness and up the fire escape to the testing station.

Now determined on the only solution available, Kerans' mind felt clear and co-ordinated again, extending outwards beyond the perimeter of the lagoon.

Only fifty miles to the south, the rain-clouds were packed together in tight layers, blotting out the swamps and archipelagoes of the horizon. Obscured by the events of the past week, the archaic sun in his mind beat again continuously with its immense power, its identity merging now with that of the real sun visible behind the rain-clouds. Relentless and magnetic, it called him southward, to the great heat and submerged lagoons of the Equator.

Assisted by Riggs, Beatrice climbed up on to the roof of the testing station, which also served as the helicopter landing stage. When Sergeant Daley started his engine and the rotors began to spin, Kerans quickly made his way down to the balcony two floors below. Separated by a hundred yards or so on either side, he was directly between the helicopter and the barrage, the continuous terrace of the building linking the three points.

Behind the building was an enormous bank of silt, reaching upwards out of the surrounding swamp to the railings of the terrace, on to which spilled a luxurious outcrop of vegetation. Ducking below the broad fronds of the fern trees, he raced along to the barrage, fitted between the end of the building and the shoulder of the adjacent office block. Apart from the exit creek on the far side of the lagoon where the pumping scows had been stationed, this was the only major entry point for the water that had passed into the lagoon. The original inlet, once twenty yards wide and deep, had shrunk to a narrow channel clogged with mud and fungi, its six foot-wide mouth blocked by a rampart of heavy logs. Initially, once the rampart was removed, the rate of flow would be small, but as more and more of the silt was carried away the mouth would widen again.

From a small cache below a loose flagstone he withdrew two square black boxes, each containing six sticks of dynamite lashed together. He had spent all afternoon searching through the nearby buildings for them, confident that Bodkin had raided the armoury of the base at the same time that he had stolen the compass, sure enough finally found the trove in an empty lavatory cistern.

As the helicopter engine began to fire more loudly, the exhaust spitting brightly into the darkness, he lit the short 30-second fuse, straddled the rail and ran out towards the centre of the barrage.

There he bent down and suspended the boxes from a small peg he had driven into the outer row of logs earlier that evening. They hung safely out of view, about two feet from the water's edge.

"Dr. Kerans! Get away from there, sir!"

Kerans looked up to see Sergeant Macready at the further end of the barrage, standing at the rail of the next roof. He leaned forward, suddenly spotting the flickering end of the fuse, then rapidly unslung his Thompson gun.

Head down, Kerans raced back along the barrage, reached the terrace as Macready shouted again and then fired a short burst. The slugs tore at the railings, gouging out pieces of the cement, and Kerans fell as one of the cupronickel bullets struck his right leg just above the ankle. Pulling himself over the rail, he saw Macready shoulder the gun and jump down onto the barrage.

"Macready! Go back!" he shouted to the Sergeant, who was loping along the wooden planks. "It's going to blow!"

Backing away among the fronds, his voice lost in the roar of the helicopter as it carried out its take-off check, he helplessly watched Macready stop in the centre of the barrage and reach down to the boxes.

"Twenty-eight, twenty-nine…" Kerans concluded automatically to himself. Turning his back on the barrage, he limped away down the terrace, then threw himself onto the floor.

As the tremendous roar of the explosion lifted up into the dark sky, the immense fountain of erupting foam and silt briefly illuminated the terrace, outlining Kerans' spreadeagled form. From an initial crescendo, the noise seemed to mount in a continuous sustained rumble, the breaking thunder of the shock wave yielding to the low rush of the bursting cataract. Clods of silt and torn vegetation spattered on the tiles around Kerans, and he stumbled to his feet and reached the rail.

Widening as he watched, the water jetted down into the open streets below, carrying with it huge sections of the silt bank. There was a concerted rush to the deck of the depot ship, a dozen arms pointing up at the water pouring out of the breach. It swilled into the square, only a few feet deep, blotting out the fires and splashing against the hull of the ship, still rocking slightly from the impact of the explosion.

Then, abruptly, the lower section of the barrage fell forwards, a brace of a dozen twenty-foot logs going down together. The U-shaped saddle of silt behind collapsed in turn, exposing the full bore of the inlet creek, and what appeared to be a gigantic cube of water fifty feet high tipped into the street below like a flopping piece of jelly. With a dull rumbling roar of collapsing buildings the sea poured in full flood.

"Kerans!"

He turned as a shot whipped overhead, saw Riggs running forward from the helicopter landing stage, pistol in hand. His engine stalled, Sergeant Daley was helping Beatrice out of the cabin.

The building was shaking under the impact of the torrent sweeping past its shoulder. Supporting his right leg with his hand, Kerans hobbled into the lee of the small tower which had held his previous observation window. From his trouser belt he pulled the.45 Colt, held the butt in both hands and fired twice around the corner at the approaching hatless figure of Riggs. Both shots went wild, but Riggs stopped and backed off a few feet, taking cover behind a balustrade.

Feet moved quickly towards him and he looked around as Beatrice raced along the terrace. Reaching the corner as Riggs and Daley shouted after her, she sank down on her knees beside Kerans.

"Robert, you've got to leave! Now, before Riggs brings more of his men! He wants to kill you, I know."

Kerans nodded, getting painfully to his feet. "The Sergeant-I didn't realise he was patrolling. Tell Riggs I'm sorry-" He gestured helplessly, then took a last look at the lagoon. The black water surged across it through the buildings, level with the top line of their windows. Upended, its paddles stripped away, the depot ship drifted slowly towards the far shore, its hull sticking up into the air like the belly of an expiring whale. Spurts of steam and foam erupted from its exploding boilers, bursting out through the gashes in the hull as it was driven across the sharp reefs of the half-submerged cornices. Kerans watched it with a quiet contained pleasure, savouring the fresh tang that the water had brought again to the lagoon. Neither Strangman nor any members of his crew were visible, and the few fragments of splintered bridge and funnel swept away by the water were swallowed and regurgitated by the boiling undercurrents.

"Robert! Hurry!" Beatrice pulled his arm, glancing back over her shoulder at the darting figures of Riggs and the pilot only fifty yards away. "Darling, where are you going? I'm sorry I can't be with you."

"South," Kerans said softly, listening to the roar of the deepening water. "Towards the sun. You'll be with me, Bea."

He embraced her, then tore himself from her arms and ran to the rear rail of the terrace, pushing back the heavy fern fronds. As he stepped down onto the silt bank Riggs and Sergeant Daley appeared around the corner and fired into the foliage, but Kerans ducked and ran away between the curving trunks, sinking up to his knees in the soft mud.

The edge of the swamp had receded slightly as the water poured away into the lagoon, and he painfully dragged the bulky catamaran, home-made from four fifty-gallon drums arranged in parallel pairs, through the thick rasp-weeds to the water. Riggs and the pilot emerged through the ferns as he pushed off.

While the outboard kicked into life he lay exhausted on the planking, the shots from Riggs'.38 cutting through the small triangular sail. Slowly the interval of water widened to a hundred and then two hundred yards, and he reached the first of the small islands that grew out of the swamp on the roofs of isolated buildings. Hidden by them, he sat up and reefed the sail, then looked back for the last time at the perimeter of the lagoon.