Richard Blade awoke. He felt hard rock under him and small sharp stones jabbing into his bare skin. His head throbbed like a drum and a searing white light dazzled him. He closed his eyes and tried to relax. It had been a remarkably swift and simple transition into Dimension X.

He could not help laughing at that idea, although the laughter made his head hurt more. He supposed a transition into Dimension X could be «swift.» At least it had seemed to him only a few seconds in the nothingness that lay between Home Dimension and Dimension X. How long it really was; he couldn't even guess. Normal concepts of time and space had less than no meaning when a man was passing from an underground room below the Tower of London into some part of infinity.

What made no sense was to call any transition into Dimension X «simple.» To be sure, there hadn't been anything unusual about this trip. He wasn't carrying any equipment and Lord Leighton hadn't sprung some new and exotic experiment ripened in his brilliant, eccentric, and endlessly fertile mind.

Blade had simply smeared himself with smelly black grease to prevent electrical burns and sat down in a chair inside a glass booth in the center of the underground room. Lord Leighton bustled about, attaching scores of cobra-headed metal electrodes to Blade's body, wiring him into the huge computer whose gray crackle-finished consoles rose all around the booth. At last Leighton returned to stand by the main control panel. With the gray-haired man known only as J watching, Leighton pulled the red master switch. Current surged into him, the computer and his own train joined, and for the twenty-seventh time Richard Blade was flung away from the room, from Britain, from the world he knew, into-somewhere else.

Very simple, until you started thinking about all that had gone into preparing this series of events that had become almost a routine.

There were only four men in the whole world who knew it all. There was Lord Leighton, the most brilliant and the most eccentric scientific brain in Great Britain. The giant computer was his creation, and in a sense Dimension X was his discovery. It had been his idea to wire Richard Blade into the computer for the first time. He thought the combination of a human and an electronic brain would produce something new and unique.

It certainly had. When Blade returned from his first trip into Dimension X, it was instantly clear that he'd returned with one of the most important scientific discoveries of all time. It had to be kept a closely guarded secret, from Britain's enemies and even from her friends. It also had to be studied further.

There was a whole world-many worlds-out there in Dimension X. There were resources of knowledge, material, skills, people-a whole new British Empire that could dwarf the first one. One scientist, one computer, and one man of action wouldn't be enough for the job.

So the Prime Minister of England was told of the discovery, and several million pounds from secret funds went to establish Project Dimension X. The man called J, head of the secret intelligence agency MI6, was told, and he became the Project's administrator, security chief, and man-of-all-work. He also kept a watchful eye on Lord Leighton's more bizarre whims and fancies, particularly when they might endanger Richard Blade. J had picked Blade straight out of Oxford, seen him become MI6's crack agent, and loved the younger man as he would have loved a son.

Lord Leighton, the Prime Minister, J. Three of the four who knew the secrets of Dimension X. The fourth was Richard Blade, the man on the spot. Secret agent, natural adventurer, a man whose physical and mental gifts made him the most nearly indestructible human being alive. Veteran of twenty-six trips into Dimension X, and the only living person who could come through one alive and sane. There were doubtless others, and sooner or later they would have to be found and put to work. Meanwhile, Blade was not only indestructible, he was indispensable.

That was by no means all of the story, if one wanted to tell it completely. There was more money, some of it spent to good purpose, much of it spent on Lord Leighton's whims. There were men and women dead all over Dimension X, killed by Blade in the process of surviving to return to Britain alive and sane.

There were men and women dead or in prison in a good many places in Home Dimension, killed or confined to protect the secret of Dimension X.

There were unexpected and totally lunatic moments, such as the time Blade saved a dozen lives in a train wreck outside London. He had to flee in order to escape publicity that might have endangered the security of the Project. Because he fled, Scotland Yard decided that he may have been a wanted criminal. For several months Britain's own police were hard at work, making it impossible for Richard Blade to live a normal life even when he was in Home Dimension. J had finally tidied up that mess, but there would inevitably be others, probably even worse.

Simple? No, the word made no sense at all here. The only way Richard Blade would ever face anything «simple» was when his luck finally ran out.

Death was simple enough, at least when it was all over.

For now, Blade was alive, safely in Dimension X, unhurt except for the usual headache, and in no danger of anything except sunburn. The sun and the hot wind blowing across his skin made him suspect he'd landed in a desert.

He opened his eyes and sat up. Sunlight flamed and his head started throbbing again. He saw gray mountains to his left, red-brown desert to his right. With the dazzling sunlight and his throbbing head, he had a moment's sensation that both the mountains and the desert were alive and watching him.

Slowly his eyes adjusted to the glare and his head calmed down. He found he could stand, look around him, and see the landscape for what it was.

He stood on a rocky slope that rose from the edge of the desert toward the mountains. A monstrous, incandescent sun poured light and heat out of a sterile blue sky. The mountains lay to the west, the desert to the east.

The desert began about five miles to the east and nearly a mile below Blade. It stretched away toward a distant flat horizon, patches of gravel alternating with patches of sand. Blade saw gulleys that must have been carved by water, but no vegetation, let alone birds or animals. In the clear air the horizon was a good thirty miles away-two days travel, for a man taking it easy and saving moisture. Every one of those thirty miles looked dead, dry, and sterile. It would be too much of a gamble heading out across the desert, Blade decided. He'd have to reach water within three days. That was as long as he could hope to last in this sun-baked land. Then he would die. In a few more days after that his body would be a withered husk. In a few months the sand would have buried him, or perhaps stripped the flesh from his bones so that only a bleaching skeleton would remain to greet travelers.

There seemed to be nothing out there worth risking such a fate. If the ground at his feet had been sprouting man-eating tigers and poisonous snakes, perhaps Blade would have thought differently. But it was only bare rock, sullen gray streaked with black and brown, cracked and flaked by thousands of years of sun, and at the moment almost too hot to stand on. To the west rose the mountains, and Blade turned to study them more closely.

The nearest peaks leaped up to at least ten thousand feet. Farther away Blade could see more peaks rising to twelve and fifteen thousand feet, with white snowcaps blazing from their summits. Still farther off he could make out the white wall of a magnificent triangular peak soaring up to at least twenty thousand feet. A plume of snow trailing from its summit hinted at strong winds high aloft.