But now, in this manufactured dream, he seemed vibrantly alive. Every sensation was solid, stimulating. He could feel his pulse throbbing through him. Somewhere out in those mists, he knew, was Odal. And the thought of coming to grips with the assassin filled him with a strange satisfaction.

Massan had spent a good many years serving his government on the rich but inhospitable high-gravity planets of the Acquataine Cluster. This was the environment he had chosen: crushing gravity; killing pressures; atmosphere of ammonia and hydrogen, laced with free radicals of sulphur and other valuable but deadly chemicals; oceans of liquid methane and ammonia; "solid ground" consisting of quickly crumbling, eroding ice; howling superpowerful winds that could pick up a mountain of ice and hurl it halfway around the planet; darkness; danger; death.

He was encased in a one-man protective outfit that was half armored suit, half vehicle. There was an internal grav field to keep him comfortable in 3.7 gees, but still the suit was cumbersome, and a man could move only very slowly in it, even with the aid of servomotors.

The weapon he had chosen was simplicity itself—a hand-sized capsule of oxygen. But in a hydrogen/ammonia atmosphere, oxygen could be a deadly explosive. Massan carried several of these "bombs"; so did Odal. But the trick, Massan thought to himself, is to know how to throw them under these conditions; the proper range, the proper trajectory. Not an easy thing to learn, without years of experience.

The terms of the duel were simple: Massan and Odal were situated on a rough-topped iceberg that was being swirled along one of the methane/ammonia ocean's vicious currents. The ice was rapidly crumbling; the duel would end when the iceberg was completely broken up.

Massan edged along the ragged terrain. His suit's grippers and rollers automatically adjusted to the roughness of the topography. He concentrated his attention on the infrared detector that hung before his viewplate.

A chunk of ice the size of a man's head sailed through the murky atmosphere in a steep glide peculiar to heavy gravity and banged into the shoulder of Massan's suit. The force was enough to rock him slightly off-balance before the servos readjusted. Massan withdrew his arm from the sleeve and felt the inside of the shoulder seam. Dented, but not penetrated. A leak would have been disastrous, possibly fatal. Then he remembered: Of course—I cannot be killed except by direct action of my antagonist. That is one of the rules of the game.

Still, he carefully fingered the dented shoulder to make certain it was not leaking. The dueling machine and its rules seemed so very remote and unsubstantial, compared to this freezing, howling inferno.

He diligently set about combing the iceberg, determined to find Odal and kill him before their floating island disintegrated. He thoroughly explored every projection, every crevice, every slope, working his way slowly from one end of the 'berg toward the other. Back and forth, cross and re-cross, with the infrared sensors scanning three hundreds sixty-degrees around him.

It was time-consuming. Even with the suit's servomotors and propulsion units, motion across the ice, against the buffeting wind, was a cumbersome business. But Massan continued to work his way across the iceberg, fighting down a gnawing, growing fear that Odal was not there at all.

And then he caught just the barest flicker of a shadow on his detector. Something, or someone, had darted behind a jutting rise of the ice, off by the edge of the iceberg.

---

Slowly and carefully, Massan made his way toward the base of the rise. He picked one of the oxy-bombs from his belt and held it in his right-hand claw.

Massan edged around the base of the ice cliff, and stood on a narrow ledge between the cliff and the churning sea. He saw no one. He extended the detector's range to maximum, and worked the scanners up the sheer face of the cliff toward the top.

There he was! The shadowy outline of a man etched itself on the detector screen. And at the same time, Massan heard a muffled roar, then a rumbling, crashing noise, growing quickly louder and more menacing.

He looked up the face of the ice cliff and saw a small avalanche of ice tumbling, sliding, growling toward him. That devil set off a bomb at the top of the cliff!

Massan tried to back out of the way, but it was too late. The first chunk of ice bounced harmlessly off his helmet, but the others knocked him off-balance so repeatedly that the servos had no chance to recover. He staggered blindly for a few moments, as more and more ice cascaded down on him, and then toppled off the ledge into the boiling sea.

Relax! he ordered himself. Do not panic! The suit will float you. The servos will keep you right-side-up. You cannot be killed accidentally; Odal must perform the coup-de-grace himself.

Then he remembered the emergency rocket units in the back of his suit. If he could orient himself properly, a touch of a control stud on his belt would set them off, and he would be boosted back onto the iceberg. He turned slightly inside the suit and tried to judge the iceberg's distance through the infrared detector. It was difficult, especially since he was bobbing madly in the churning currents.

Finally he decided to fire the rocket and make final adjustments of distance and landing site after he was safely out of the sea.

But he could not move his hand.

He tried, but his entire right arm was locked fast. He could not budge it an inch. And the same for the left. Something, or someone, was clamping his arms tight. He could not even pull them out of their sleeves.

Massan thrashed about, trying to shake off whatever it was. No use.

Then his detector screen was lifted slowly from the viewplate. He felt something vibrating on his helmet. The oxygen tubes! They were being disconnected.

He screamed and tried to fight free. No use. With a hiss, the oxygen tubes pulled free of his helmet. Massan could feel the blood pounding through his veins as he fought desperately to free himself.

Now he was being pushed down into the sea. He screamed again and tried to wrench his body away. The frothing sea filled his viewplate. He was under. He was being held under. And now ... now the viewplate itself was being loosened.

No! Don't! The scalding cold methane ammonia sea seeped in through the opening viewplate.

"It's only a dream!" Massan shouted to himself. "Only a dream. A dream. A—"