"Many other instances. An Italian record of a stranger who appeared mysteriously in Sicily some two hundred years ago in a machine, the description of which shows a marked resemblance to a rocket-propelled airship. Legend relates that this wise man, who spoke a curiously distorted English, made his home with the natives for several months, taught them new and better methods of husbandry, instructed them in the construction of mechanical devices, and stayed an incipient plague by medical means unknown to that era." "Still," expostulated Ramey, "to travel across Time--" "As a hazard," pursued the old man, "let us suppose the continuum of Space-Time may be likened to a huge volume in which is inscribed all the history of past, present, and future. All things are written there--_all_. From man's darkest beginnings till the last feeble flutter of a dying sun stills in cold death a forlorn earth. Man, reading this volume, must perforce turn the pages one by one. He has memory of that which he has read, comprehension of that upon which his eyes presently rest--but no knowledge whatsoever of what lies before. "But there is another pathway through this volume. The creeping pathway of the bookworm. This is the shortest route between era and era. Through this infinitesimal tunnel the bookworm--or let us say a 'time machine' constructed by one who knows the manner of its making--can skip from epoch to epoch in the twinkling of an eye." Ramey stared at him incredulously. "And you--you think this thing we're in may be a sort of mechanical bookworm piercing the pages of Time?" "I do not know," Dr. Aiken told him again. "I simply point out that at least hypothetically these things could be. I do not know; no. But we will learn in a minute. For, see? The needle has stopped. And if I am not mistaken, the humming, too, has ended." He pointed. The moving needle had indeed completed its circuit and come to rest; the vibration was gone. Whatever had been the nature of the metal chamber's movements, it was motionless now. Red fidgeted impatiently above them. "All right now, Doc? Okay for me to lift the trap now?" "Yes. By all means, Barrett." * * * * * Red raised the trapdoor gingerly. But no sunlight filtered into the inch-wide slit. He lifted it still farther, glanced anxiously down at his companions. "Hey, lookit! This is funny! It's dark! No, wait a minute--there's a little spot of light. And there's _another_ wall here and _another_ ladder." "Give him the torch, Syd," cried Dr. Aiken. "There.... Got it, Barrett? Go on up. Climb the ladder. See if you can find out where we are, and what--" The flaming brand bobbed upward ten, twenty feet, for a few seconds weaved in uncertain circles, its light reflecting to those below only a gray formlessness and the foreshortened outlines of the climbing Barrett. Then: "Ramey! Doc!" cried Red. "What is it?"