"Get him before he alerts the others!" Austin shouted. But Zavala was already on his way.

Austin and Barker were left alone. With the smile still pasted on his ghostly face. Barker said, "Seems as if this is between you and me, Mr. Austin."

Austin returned the smile. "If that's the case, you're through." "Brave words. But consider your position. Umealiq will kill your partner, and within moments, armed men will come pouring through that door."

"Consider your position, Barker." He raised the sword and ad- vanced. "I'm about to cut your cold heart out and toss it to your mu- tant monsters."

Barker spun around like a ballet dancer, snatched a harpoon off the wall of the Eskimo display and, with a flick of his wrist, hurled it at Austin with amazing accuracy. Austin stooped to avoid the mis- sile. The harpoon buried itself in the chest of one of the mummies. The stand holding the mummified body in leather crashed over, pulling down the section of airship skin with the word Nietzsche on it. Barker snatched another harpoon off the wall and charged at Austin, with an ivory knife from the display in his other hand.

Austin lopped off the harpoon point with a quick swing of the sword, but the movement left him open. He stepped backward to avoid the knife and stepped on the horn, which was lying on the floor. His ankle buckled and he fell. Barker yelled in triumph and lunged. Austin had landed with the sword under him and couldn't bring it to a defensive position. The knife slashed down. Austin blocked Barker's wrist with the edge of his hand. He tried to grip it, but his palm was sweaty. He let go of the sword and brought his other hand around and used it to push the knife point away from his throat.

Frustrated by Austin's superior strength, Barker jerked his hand back and brought it up to strike again. Austin rolled out of the way, leaving the sword behind him. They both scrambled to their feet at the same time.

When Austin went to retrieve the sword, the knife slashed the air a few inches from his chest. Barker kicked the sword out of reach, then advanced on Austin. He stepped back and felt the edge of the desk behind him. He could go no farther. Barker was so close, Austin could see his face reflected in the sunglasses. Barker smiled and raised his knife to strike.

Zavala had bounded through the doorway and stopped short. He expected to find himself in another corridor. Instead, he was in a small chamber, not much bigger than a telephone booth, with ladder rungs running up one wall. A single wall lamp lit the cramped space. Under the lamp was a flashlight rack. One of the lights was missing. He grabbed one of the remaining flashlights and pointed it up. He thought he saw a flicker of movement in its beam, then nothing but darkness. He slung the rifle over his shoulder, tucked the light in his belt and began to climb. The shaft opened onto a passageway con- structed in a triangle of interlocking girders. Probably part of a keel that kept the airship rigid and allowed access to its innards.

The keel intersected another passageway. Zavala held his breath and heard a slight ting that could have been made by a boot or shoe slapping against metal. He stepped into the new passageway and found that it curved up against the inside of the zeppelin's skin. The white fabric of the inflated gas bags was pressed tightly against the framework on the other side. He guessed that he was inside a ring that worked with the keels to give the airship further support.

His theory proved out, as the passageway began to curve back on itself, so that he was climbing directly over the huge bags. Zavala was in good shape, but he was panting heavily when, at the top of the zep- pelin, he came to another triangular passageway running lengthwise from the front to the back of the airship. The choice was easier this time. He pointed his light along the transverse support. He could see movement and hear heavy footsteps echoing in the distance.

Zavala dashed along the keel, knowing he had to stop Scarface be- fore he made it to the control car and raised the alarm. He came to another juncture where the transverse corridor intersected a sup- porting ring. There was no sign or sound of Scarface to reveal where he had gone. Zavala's mind assembled a picture of the inside of the great airship.

If he were looking at a clock, the corridor he was in would be in the noon position. The transverse passageway he had seen earlier was at eight o'clock. To keep the rings rigid, there must be a third horizontal passageway at four o'clock. Maybe he could cut Scarface off at the pass.

He descended the ring, half climbing, half falling. He almost shouted in exultation when he came upon the third transverse pas- sageway. He ran down the corridor, pausing at each ring to listen. He was guessing that Scarface would make his way as far forward as he could before descending to the control car using another ring.

At the third juncture of a keel and a ring, Zavala heard a ting-ting as someone climbed down the metal ladder. He waited patiently until he could hear heavy breathing. He flicked on the light. The beam caught Scarface clinging to the ladder like a large, ugly spider. Scarface saw that he'd been intercepted and began to climb up the ladder.

"Hold it right there!" Zavala ordered. He brought the shotgun to his shoulder.

Umealiq halted and looked down at Zavala with an ugly leer on his face. "Fool!" he shouted. "Go ahead and fire. You'll be signing your death warrant. If you miss me and hit a hydrogen bag, the air- ship will go up in flames and you and your partner will die."

Zavala's lips twitched at the ends. As an engineer, he was well- acquainted with the properties of various elements. He knew that hy- drogen was volatile, but unless he was using a tracer bullet, combustion was unlikely. "That's where you're wrong," he said. "I'd just end up punching a hole in the gas bag."

The evil smile vanished. Umealiq bent off the ladder and pointed his gun at Zavala. The shotgun boomed once. The heavy shell hit Umealiq squarely in his broad chest and knocked him off the ladder. Zavala stepped back to avoid the body that crashed to his feet. As his life ebbed, Umealiq's face was twisted in disbelief.

"That's something else you were wrong about," Zavala said. "I don't miss."

While Zavala was chasing Scarface, Austin had been fighting for his life. Again, he had thrown his left hand up so that the edge of it caught Barker's wrist and stopped the descending knife inches from his neck. With his right hand, he reached up to grab Barker by the throat, but the other man jerked back. Austin's groping fingers yanked off the sunglasses. He found himself staring into Barker's pale-gray snake-eyes. Austin froze for a second and lost his grip on the wrist. Barker jerked his arm back, prepared to make another thrust.

Austin reached back onto the desk, his fingers in a desperate search for a paperweight or something else he could use to brain Barker with. He felt a searing sensation. His hand had touched one of the halogen lamps that illuminated the map. He grabbed the lamp, brought it around and shoved it in Barker's face, hoping to burn him. Barker blocked the lamp, but he couldn't stop the light. It was as if Austin had thrown acid into Barker's light-sensitive eyes. He screamed and threw his hand in front of his eyes to shield them. He stumbled back, scream- ing in the Kiolyan language. Austin watched dumbfounded at the damage he had wrought with a single lightbulb.

Barker groped his way out of the room. Austin picked up the sword and went after him. In his haste to catch Barker before he could get back to the control car, Austin was less careful than he should have been, and Barker was waiting for him in the fish hold. He ambushed Austin from just inside the door, and his slashing knife caught the rib cage on the side opposite from his existing wound. Austin dropped the sword and tumbled off the gangway onto the plastic lids that covered the fish tanks. He felt a warm dampness soaking his shirt.