"There is a sun," cried the girl, "but you can't see it. It's concealed behind a huge dome of impervite—a sort of leaded, polarized glass. Harg told me all about it while you were unconscious.
"In the year 17,000 A.D., or thereabouts, there was a terrible catastrophe on Earth. Man's constant drainage of electrical energy created a rupture in the Heaviside layer, and the layer collapsed. As you know, the Heaviside layer is Earth's only protection against potentials from space, from the undiluted strength of the Milliken rays.
"Without that protection, life on Earth was doomed. So large areas were domed over with this sixty-foot-thick layer of impervite. And—"
"And in the meantime," interrupted Larry, "intense subjection to cosmic radiation, along with the increasing use of telepathy, turned the human race's hearing apparatus from a useful organ into a vestigial one."
"And one," agreed the girl, "sensitive as the nerve of a tooth. It must be that. It couldn't be anything else. So there is Harg's weakness. Now, if we can only find some way to play upon it—"
Larry said gloomily, "But he still is the only one who can return us to our own time."
Sandra's hand touched his swiftly, confidently.
"We'll find some way to make him," she whispered. "We'll do it, you and I—"
Even under these circumstances Larry Wilson found the touch of that hand thrilling, the confidence of Sandra's voice, with its "you and I," endearing. It was a jest of the gods that this new glory should have come to him at last in such a situation. But the year mattered little. Time or no Time, he knew, and he thought she knew—