Suddenly a second taller figure detached itself quickly from the darkness behind Hardoon, bent across the desk and pressed a button on the control panel.

Immediately the sounds dimmed and fell away, and the ceiling lights came on overhead. Hardoon looked over his shoulder in surprise. He pulled himself out of his reverie, and gestured impatiently at Kroll, who was covering Maitland and Lanyon with his.45.

Maitland called out: "Hardoon! Listen, for God's sake! The bunkers are flooding, the foundations are caving in!"

Hardoon stared at him sightlessly, apparently unaware of Maitland's identity. His eyes focussed uncertainly on the wall behind Maitland's head. Then he motioned again to Kroll with a snap of his fingers and turned back to the window.

"Hardoon!" Maitland shouted. He and Lanyon began to move forward, but Kroll leaped quickly around the desk, the large automatic holding them off.

"Turn around, both of you!" he snapped, pushing Maitland back with a heavy fist. They sidestepped out into the hall, and Kroll closed the doors behind him. Flicking the barrel of the gun, he steered them into the elevator, then stood two yards away from them, left hand on the control switch, ready to close the doors, his right leveling the gun, first at Lanyon and then at Maitland.

"Kroll!" Maitland shouted. "The shelters are collapsing! Four hundred men are trapped in there. You've got to get them across here.

Kroll nodded coldly, his mouth tight, his eyes like black chisels under the visor of his helmet. He raised the barrel at Maitland's head, his jaw muscles tensing, bunching the skin into hard knots.

As his finger squeezed the trigger, Maitland dropped quickly to his knees, trying to avoid the bullet. He looked up, saw Kroll grunt and train the gun on him again. Lanyon had backed up against the side of the car, stabbed frantically at the control buttons.

Waiting for the bullet to crash into his skull, Maitland lowered his head.

Suddenly, without warning, the floor tipped sharply, knocking him against the side of the elevator. As he straightened himself he heard the roar out, felt the bullet slam past his head into the leather padding, ripping a three-inch slash across it. Flung off his feet, Kroll lost his balance and tripped across the small table by the reception desk.

As he picked himself up, swearing in a low snarl, Maitland dived forward at the automatic held loosely in his hand. Above their heads the lights swung eerily, and the floor remained tilted at a slight angle.

"Lanyon!" Maitland shouted. "Get his gun!"

Behind him, Lanyon dived out of the elevator and hurled himself onto Kroll.

As they staggered across the sloping floor, Lanyon slammed a heavy punch into Kroll's neck, pounding the big man with the full force of his weight. Kroll rolled with the blow, holding off Maitland with his left arm, trying to free the automatic Maitland had seized with both hands.

For a moment they struggled tensely. Butting with his head, Kroll drove the heavy helmet up into Maitland's face. Maitland gasped for breath and sat down on the floor, grabbing Kroll's jacket with one hand and pulling the big man on top of him. Kroll pulled himself up onto his knees, sitting astride Maitland, and knocked Maitland's hands away with a heavy left swing. As he rammed his forefinger into the trigger guard and leveled the automatic at Maitland's chest, Lanyon picked a massive glass ashtray off the reception desk beside them and brought the edge down across the narrow strip of exposed neck below Kroll's helmet.

The big man began to slump and Lanyon reached down and turned him by the shoulder and then slashed him again across the face with the ashtray, knocking his head backward onto the top of the desk, his face like an inflamed skull's.

"You've got him," Maitland gasped. He stood up and staggered back against the wall and Kroll sank loosely onto his knees and then collapsed across the floor, blood running from a deep wound behind his ear onto the carpet. Maitland picked up the automatic, held the butt in both hands. "God, that was close!"

Lanyon tried to find his balance on the angling floor. "What the hell's happening here? The whole pyramid seems to be tipping over!"

The down light flashed in the indicator panel over the elevator.

"Warning!" Lanyon said. "Come on, let's get out of here."

"Wait a minute," Maitland told him. Gripping the automatic carefully, he ran up the incline toward Hardoon's office.

The room was in darkness, the only light coming from the observation window. Books had spilled from the high shelves and lay across the floor, chairs and tables had careened over to the far wall. Hardoon had been thrown heavily off balance, was pushing himself back to the window along the edge of the desk.

Maitland had started to move toward him when the floor tilted again, dropping an inch below his feet like a jerking elevator. He stumbled, saw Hardoon pitch sideways across the desk. Books cascaded from the shelves like toppling dominoes. Hardoon regained his footing, seized the window ledge with both hands and pulled himself back.

Maitland crossed to the desk, stepped around it and touched Hardoon on the shoulder. The millionaire looked back at him blindly, the flickering light outside illuminating his storm-riven features.

"Hardoon!" Maitland shouted. "Get away from here!"

Hardoon shook him off, turned to the window. For a few seconds Maitland stared out at the scene below. The storm wind swept by at colossal speed, the dark clouds now and then breaking to reveal the dim outlines of the fortified shelters. The two long buttress walls had disappeared. In their place an enormous ravine, at least 100 feet deep, had opened in the ground, and a swift torrent of water emerged from the mouth of a huge rift and ran straight below the left-hand corner of the pyramid, carrying with it an everincreasing load of debris swept from the exposed sides. On the extreme left, protruding out through the wall of the ravine, Maitland could see the sharp rectangular outlines of part of the main bunker system, the communications tunnel straddling the ravine like a bridge. Once fifty feet below ground, it was now completely exposed for almost a third of its length. Behind it were the square ledges and walls of other portions of the bunker, their unsupported weight wrenching huge cracks in their surface.

The floor tilted again, throwing the two men against each other. Maitland steadied himself, helped Hardoon back onto his feet. The older man clung forward at the window, holding it desperately.

"Hardoon!" Maitland shouted again. "The entire pyramid is toppling! For God's sake get out while you can! Look down there and see for yourself, the foundations are being carried away."

Hardoon ignored him. Eyes glazed, he stared obsessively into the night, watching the whirlwind of black air.

Maitland hesitated, then left him. As he crossed the room the floor sank abruptly and one of the bookshelves fell forward and crashed down across a chair. Maitland ducked past it, pausing at the door to look back for the last time at Hardoon. By now the angle of the floor was almost ten degrees, and the millionaire was staring upward into the sky like some Wagnerian super-hero in a besieged Valhalla.

"Maitland!" Lanyon shouted urgently. He was standing by the elevator shaft, gesturing. On the floor beside him Kroll stirred slowly, drawing his long legs together.

Maitland stepped quickly into the lift. "We'll leave him here," he said to Lanyon. "Perhaps he can save Hardoon." He stabbed the ground button, and the elevator slipped and then sank slowly down the shaft.

Waring and Patricia Olsen were crouching by the tunnel entrance as they stepped out, glancing up anxiously at the tilting ceiling.

"There's every chance that the whole pyramid will keel over," Maitland said. "Our best hope is to get back into the bunkers. Once the channel forces its way past the pyramid the shelters should drain again. Already they're well above the floor of the ravine."