had vanished.
"Just think — they're already back in their own universe, billions of light-years away!" marveled Tiko.
"I didn't like the way that girl eyed you," Joan told Captain Future half seriously. "I'm going to watch you when we reach her universe."
"When we reach it?" echoed Curt, startled. "Listen, Joan — you don't by any remote chance think I'm crazy enough to take you along on as dangerous a venture as this?"
Joan's brown eyes grew stormy.
"Do you think I'd let you go off without me to a universe where all the women are platinum blondes?"
Curt chuckled, but then grew sober.
"Joan, listen — it's not just the danger you'd run that I'm thinking of. Someone ought to be here to help Tiko guard the matter-transmitter. If anything happened to it, we'd never be able to get back here."
"That's just an excuse to leave me behind," Joan declared indignantly. Then her face softened. "Oh, all right, Curt — I don't want to make it difficult for you. I'll stay here."
The following few weeks marked intense labor and preparation by the Futuremen. Out in the grounds of Tiko Thrin's little estate they constructed the larger matter-transmitter that was required. It was of the same basic design as the laboratory model, but its huge transparent chamber was ovoid in shape, the more easily to accommodate the Comet.
During intervals snatched from their work, Curt Newton and the Futuremen learned the Tarast language as best they could from Tiko Thrin. The big new transmitter rapidly took shape. But frequently the work was delayed when the Brain went into one of his reveries of abstract scientific speculation, from which it was hard to arouse him.
"I'm trying to fathom the theoretical basis of these transmitters," Simon Wright replied when Captain Future protested. "You know, lad, I still can't believe that the fourth dimension is really spatial in nature."
Joan asked a puzzled question.
"But, Simon, when we were fighting those Alius on the comet-world, you and Curt always referred to the fourth dimension of space."
"We meant the fourth spatial dimension," the Brain corrected. "That is really the fifth dimension, for according to the theory of relativity, the true fourth should be non-spatial."
Curt was impatient.
"Simon, in spite of the tenets of relativity, we know the fourth must be spatial, for we've seen that Tiko's power-beam can traverse it. We've no time now for theoretical considerations. We can investigate the theory of it later."
"Oh, very well," muttered the Brain. "But I still can't understand it. Neither can Tiko, for he simply adapted the apparatus of the alien Alius without investigation of its underlying principles."
The big transmitter finally was completed. Its huge ovoid chamber glittered like a great jewel on the green breast of the Garden Moon, crowned by the towering antenna of copper planes in curious arrangement.
The night of the Futuremen's start was at hand. At this prearranged time, Gerdek and Shiri would be expecting them at the big receiver they had been building in their faraway universe. The Comet had already been eased into the ovoid chamber.
Joan clung to Captain Future.
"I'm afraid, Curt. I never felt this way before. A remote, alien universe — and you're going there to carry out an impersonation that means death if you're discovered. It frightens me."
"And I thought you were a real planeteer," he reproached her with pretended severity.
But he held her close, before he strode away.
JOAN stood in the planet-glow, rigid with emotion as she watched Curt's tall, lean figure enter the sleek little ship in the chamber. She caught the final wave of his hand from the control room, as Tiko Thrin closed the chamber and hastened to the switchboard.
A bursting blaze of shining force suddenly enwrapped the interior of the chamber and hid the Comet. Thousands of threads of lightning seemed to stream out of the haze toward the tiny copper electrodes that lined the chamber. Then they