There were four people in the office. They were the only four people in the world who were supposed to know all about Project Dimension X. There was Richard Blade, the project's front-line soldier. He had made sixteen trips into Dimension X. No other living man had made even one and returned alive and sane. There were hopes that someone might turn up sooner or later, but so far all the searching had not disclosed that someone.

There was Lord Leighton, as brilliant as he was temperamental, Britain's leading computer scientist. The great computers under the Tower of London that sent Blade into Dimension X were his creation. His small dark eyes behind their thick glasses flicked irritably around the room. Occasionally he would shift position in his chair, trying to get more comfortable. That was hard, with a body distorted by polio, a hunchback, and eighty-odd years.

J returned Leighton's glance imperturbably. Everything about J seemed ordered and disciplined, even the lines in his face and the iron-gray hair receding from his high forehead. The imperturbability was not a pose, either. J had been a spy and then a spymaster for all the years of a career that went back to World War I. If he had been the type to lose his head, he would long since have been dead. He had picked Richard Blade out of Oxford, watched his career as an MI6 agent for nearly twenty years, then seen him move on to Project Dimension X. He was never happy about seeing the man he loved like a son hurled off into the unknown. But neither he nor Blade would ever balk at doing for England what needed to be done.

Nor would the fourth man in the room, the Prime Minister. He seldom sat in on these policy conferences for the project. He did not understand most of what was discussed, and admitted as much. He was a skilled politician, not a spymaster, scientist, or man of action. He held the pursestrings, tried to satisfy the project's voracious appetite for money, and kept an eye on the big picture. That last was why he was here now. A threat to the security of the project was a threat to the security of England, and perhaps to the whole free world.

«-so the men themselves have no apparent ties with any foreign government,» J was saying.

Before J could go on, the Prime Minister interrupted him. «Does that mean we needn't worry about major security leaks?»

J shook his head more sharply than usual. Silly questions of that sort had annoyed the older man as long as Blade had known him. «It means nothing of the kind. I said 'no apparent ties.' We have to dig deeper. And there's the girl, Elizabeth.»

Blade stiffened slightly in his seat. It was damned unprofessional of him, to be sure, but he was concerned about that poor girl.

J gave him a reassuring smile. «She says she was pushed into it by a threat to her family. They're still in Czechoslovakia. So if the people who threatened her aren't Soviet agents themselves, they're certainly working for somebody who's in contact with the Soviet intelligence apparatus.»

«What about one of the big industrial espionage firms?» put in Blade. «I wouldn't put it past some of them to try a caper like this, if the money was right.»

«Neither would I,» said J sourly. «We're checking that possibility right now.»

«But what about Elizabeth herself?» asked Blade.

Again J smiled. «We've tested her story every way we could. She seems to be telling the truth. We're going to push an inquiry back through our Czech network to get further confirmation. If that also puts her in the clear, we're going to stop worrying about her. We'll give her a new identity and arrange for her to emigrate to Canada without any fuss or bother. Of course we'll be keeping her under surveillance for a year or two, but that will be more for her own protection than ours.»

Blade could not hold back a sigh of relief, which drew another smile from J. Then the older man's manner became brisk and businesslike again.

«We'll push inquiries about the gunmen themselves in every possible direction,» he went on. «I'd rather not compromise any of our key people, of course, but if necessary…» He left the sentence unfinished, but Blade at least could fill in the missing words with no difficulty. «In any case, it will be a considerable aid to us if MOD can also move on the matter.» He looked at the PM.

The PM nodded. «Certainly. Ministry of Defense has as much of a stake in this as anybody else. But it's going to mean delaying MOD support for some of the related projects, like the new people and the training center.»

«Right now, they're not that important,» said J. Blade knew that statement must be costing the other man a good deal. For years J had dreamed above all of finding someone else besides Blade to travel into Dimension X. «If the project has been seriously compromised, we're going to have some very hard decisions to make.»

«Not to mention expensive,» said the Prime Minister sourly. He knew from long and weary experience that any major changes in the operation of a project this size usually carried a price tag in six figures.

«I'm afraid so,» said J bluntly. «Then there's Richard. I doubt if there's going to be another attempt to snatch him soon, not with our investigation hopefully putting the opposition on the defensive. But I'd feel a great deal better if he were somewhere they couldn't possibly get at him for a while. And I can't think of any better place than Dimension X.» He looked at Lord Leighton. «How soon could you set up the computer to send Richard off?»

Lord Leighton considered the matter for a few seconds. Then he shrugged his thin, bowed shoulders. «I was planning to down-line the main computer for about ten days to incorporate some of the Controlled Return devices. But if all you want is the conventional techniques-well, what about tomorrow?»

«Tomorrow will be fine,» said Blade.

«Then tomorrow it is,» said J.

And it was the next morning when Blade presented himself at the Tower of London. The Special Branch men, clothing as dark as the gray sky overhead, led him to the head of the secret elevator. The massive bronze doors closed behind him, and the elevator car plunged two hundred feet straight down to the level of the secret complex below the tower.

This morning J was too busy with his investigations to see Blade off. So Blade walked down the long, gleaming corridor and through the electronically guarded doors by himself. He heard the clatter of typewriters and the faint murmur of laboratory equipment from behind closed doors on either side as he walked. But he met no one until he reached the door to the central complex. There Lord Leighton himself met Blade.

«Ah, Richard,» the scientist said with a grin. «Prompt as usual. I started the main sequence ten minutes ago, assuming you'd be on time. And I was right. You'd have made a first-class scientist, Richard. You've got the proper taste for precision.»

Blade smiled. «Perhaps. But I don't think I have some of the other gifts.» Lord Leighton was unbending more than usual, but Blade didn't really feel much like conversation. He was always more or less on edge as he approached the moment of being hurled into Dimension X. And the attempt on his life still bothered him somewhat. He lived with danger in Dimension X, but it was a long time since he had been in any danger here in England.

As always, the ritual of preparing for the journey eased the strain. Blade went into the small changing room and stripped to his skin. Then he smeared every square inch of that skin with a foul-smelling black grease, used to prevent electrical burns from the massive jolt of current that would be passing through his body. Then he knotted a loincloth about his waist. That never did anything to justify the trouble of putting it on-Blade had always arrived in Dimension X naked as a newborn baby.