Now there were vibrations almost too heavy in this miniature region to be called sounds. They were more like earthquake shocks. But Ed realized that they were just the noises of normal human movement—the giants Ed, Barbara and Mitch putting on their boots, the grind of their footsteps. Meanwhile they conversed, it seemed; but their voices were only a quiver, a rattle, with a hint of worried inquiry. The giant Mitchell Prell seemed to make suggestions.

The lesser Prell must still have understood what was being said. For now he gripped a roughly made microphone and talked into it. His words were amplified to a seismic temblor as they emerged from the sound cone on the far wall; but to Ed and Barbara they were still directly audible from the speaker's own lips. "You've come down to me successfully. Now we must see what will happen. Ed, if it is only the police at our gates, perhaps it would be best simply to present yourselves as citizens. You and Barbara have rights. And you've fulfilled your pledge to them. They can't harm you. Beyond this, I must apologize to you both. You have made a difficult journey to what must seem to you a frustrating blank wall—without experiencing anything very new. That is a defect of being duplicated. And there is no time now to blend into your minds the memories of the descent into smallness. I'm sorry. Mitchell Sandhurst Prell—yes, you, my overgrown former identity—show them what to do. But for heaven's sake, move this workshop of mine to a slightly less exposed place!"

Because he was like his old self, the smaller Ed Dukas still thought as his original did. So, after all, there was that much contact. He understood the frustration that had just been mentioned, plus the confusion of not having seen the reality of another size level. This failure could even involve suspicion of his uncle's purposes. But there was loyalty and belief, too. From the basis of parallel minds, the lesser Ed felt all these emotions personally.

So he moved quickly, closer to the tiny microphone, bent on giving reassurance. He shouted into it; and of course his words came out sounding somewhat mad: "Ed, it's me! Ed! Honestly! And that was a real Mitchell Prell speaking. Take care of yourself—and Babs—because you're me—or still part of me. And we both love Barbara—in any form. Hello, Barbara, darling."

There was no time to say any more, for now there began a steady, heavy vibration, growing gradually stronger. In a moment he guessed what it was. A huge, high-speed drill had been brought into play against granite. Very soon now these caverns would be invaded.

And more was happening. There were more seismic temblors. A colossus moved nearer, bringing its shadow; its wet clothing seemed to be woven of cables instead of thread. The face, briefly glimpsed, was a huge, pitted mask, bearded with a forest of dark and tangled trunks. A wind came with him, caused by his motion. He was that other Prell.

"Hang on!" his tiny android likeness yelled.

Ed of the dust-grain region drew his Barbara down. They flattened together and clutched part of the intricate but roughly made apparatus attached to the vats from which they had emerged, just as the glassy floor under them tilted, and they were almost swept away by gusts of air. Wires had been disconnected, and now the whole assembly—large microscope with the miniature machine shop, middle-sized tank and middle-sized doll figure under it, and the lesser electron microscope with its similar though reduced equipment—was being carried and hoisted.

It was set on a high shelf. And what must have been a translucent jar was placed in front of it to hide it casually. Maybe there was no time for anything else, for that rough vibration of the drill was becoming rapidly more pronounced.

"They ought to put on oxygen helmets!" Barbara shouted in the quaking tumult. "These vaults will be unsealed! And they aren't built to live in Martian air!"