«Lord Leighton?» J called out. The bare rock walls threw back a disquieting echo.

«There he is.» Richard pointed.

Lord Leighton, in a rumpled green smock, had blended in so well with his beloved computers he had been almost invisible. The machines were not, as they had been, dull gray with crackled finishes, but, except where a spot of gleaming chrome or spotless red plastic showed its contrast, all were in the same muted matt green as Leighton's smock.

«Ah, welcome, welcome!» Lord Leighton came scuttling forward. «How do you like my new toys?»

Leighton was a monster, a troll, a grotesque Quasimodo lurching along with a halting, crablike gait on legs that had never quite recovered from a near-fatal childhood attack of polio. Yet under his high balding forehead with its sparse strands of white silky hair pulsed a brain of terrifying power. In the field of computer technology Leighton might well be the greatest genius England-indeed the world-had ever seen. Every device in this project had begun as a gleam in these dark-pupilled yellow-rimmed bloodshot eyes that now stared up at J through the thick distorting lenses of a pair of steel-framed glasses.

J replied uncertainly, «Very pretty toys. Very pretty.»

Leighton extended a small dry claw and J shook hands with him. Toys? Was it proper for a man of Leighton's advanced age to go on prattling about toys?

Now Leighton was shaking hands with Blade, bubbling over with gargoyle enthusiasm. «I've solved it at last,» the little man boasted. «At least I think I have!»

«Solved what?» Blade was grinning, caught up in the scientist's excitement.

«Our most challenging problem of all. Before this we've never been able to send you to the same place twice, except by accident. If I'm right in my theories and calculations, I can now, once I've established the coordinates, send you again and again to the same destination. The replicator is ready!»

J raised a questioning eyebrow. «Really?» J had all but given up on this part of the project. From the beginning the replicator had been top priority, yet it had never come to fruition.

J did not become infected with Leighton's high spirits. Instead he looked around once again at all the new equipment, and his sense of impending disaster returned stronger than ever. New equipment? That meant untested equipment, hazardous experiments made more hazardous. Again and again Lord Leighton's demonic device had hurled Richard into other universes, other dimensions that no one before had dreamed existed. Somehow it had dragged him back each time, sometimes seconds before some particularly unpleasant death. The very names of the places he'd been rung with a shimmering occult sonority. Tharn! Sarma! Jedd! Patmos! Royth! Zunga!

Where were these places? In the distant past or the distant future? On planets that circle other suns in this galaxy or some other? In divergent or parallel time tracks, worlds that might have been? In universes that coexisted with this one, but which we could not see? J had no idea. With each trip the whole bloody business had become harder to understand. Even Lord Leighton, full of glib explanations at first, had gradually become as baffled as Blade and J.

Yes, though nobody honestly knew what they were doing, the experiments went on. Perhaps the time had come to halt, to stop doing and start thinking.

But Leighton was clutching J by the arm, saying, «Come along, old chap. The best is yet to come.» J allowed himself to be half-dragged toward the innermost computer room, the place where the impossible had happened already so many, many times.

J hung back when they reached the massive entrance door. «Perhaps it would be better to wait, to be careful… «

It was Blade, surprisingly enough, who answered, «No! I want to go.»

J studied the younger man a moment. It's said one can become addicted to anything. Was Blade addicted to the machine? Here was a possibility they'd never considered, a dangerous possibility. And what if Blade found on the «other side» a world he liked better than stodgy old England? Could the computer bring Blade home against his will?

The door opened.

Blade and Lord Leighton went in, J trailing behind.

Lord Leighton had been chattering on all this time, and Blade, listening intently, had been nodding at intervals and asking questions in a low voice.

«As you see, the most drastic changes are the ones I've made in here,» said the hunchback proudly, gesturing toward the place where once the familiar electric-chairlike device had stood. With alarm J noted that a new contraption occupied the center of the room, a sort of upright Iron Maiden or Egyptian mummy case, but with a tangle of wires attached to it.

Lord Leighton was explaining, «This case is molded so that it fits you exactly, Richard my boy. No one else can use it. And all the electrodes that I used to attach to you, one at a time, are now pressed into positive contact with your body automatically when the box closes.»

«Interesting,» said Blade. «A definite improvement.»

«A part of an overall plan,» said Leighton. «The replicator, you see, is not a separate unit to be plugged into a preexisting whole. It is a strategy for the organization of the entire process. When I put the electrodes on by hand, there's no way I can ever put them on exactly the same way twice. I, myself, was inadvertently introducing variation into something that must be exactly the same every time. And look here.» He gestured toward a completely remodeled control console. «I have eliminated the red sliding switch you've so often seen me throw an instant before you-er-departed.»

«Then how do you start the final sequence?» asked Blade.

«I don't. Once the program is fed into the computer memory banks, only two switches remain active: Program Start and Program Stop. And when Program Start is pushed, the preliminary sequences begin and run themselves out, one after the other. That's nothing new. The innovation is that the impulse that starts the final sequence comes directly from the computer, automatically, when it comes to the end of the prelims. I never touch the controls unless I think something is going wrong. Then I hit Program Stop. Normally everything is completely automatic, including the closing of the box. The computer even turns itself off after you've been launched»

Blade asked, «What's the point of that? Oh wait, I see. The machine repeats every step exactly the same way every time, and thus should produce the same result, so long as nobody changes the program.»

Leighton beamed up at him. «Exactly! You should have been a scientist, my boy. You have the mind for it. What we had failed to see was that no human being could do things as perfectly as a machine, not even a human being as unusual as myself.»

Blade smiled at Lord Leighton's unconscious egotism. The scientist continued, «The only variation that remains is your thoughts. You must try to think of the same things every time you're going to the same place. Do you think you can do that?»

«I can try.»

«Excellent! Tonight we'll only do a quick one. We'll send you through for ten minutes, no more. Then the computer will bring you back. Do you think that in ten minutes you can somehow make note of where you are well enough to recognize it again?»

Richard nodded. «There's always a moment of wild dreamlike disorientation before my mind focuses on the other world, but I don't think that takes up much objective time. There used to be an undetermined period of unconsciousness after I passed through, but I think that's dwindled down to nothing or next to nothing. I believe I made the trip to the Empire of Blood without blacking out at all, and the customary headache passed away very quickly. As Dostoevsky once said, 'Man is the only animal who can get used to anything.' Is that all you want me to do? Look around and see where I am?»