The huge mechanism advanced upon us. "If you resist me," it murmured menacingly, "I will be obliged to kill you. I--I cannot be controlled." It chained us now with longer chains than before. Tugh looked up from his seat at the instrument table. "Very good," he said crisply. "You may look out of the window, you two. You may find it interesting." We were retarding with a steady drag. I could plainly see trees out of the window--gray, spectral trees which changed their shape as I watched them. They grew with a visible flow of movement, flinging out branches. Occasionally one would melt suddenly down. A living, growing forest pressed close about us. And then it began opening, and moving away a few hundred feet. We were in the glade Tugh mentioned, which now was here. There was unoccupied space where we could stop and unoccupied space five hundred feet distant. Tugh and Migul were luring the other cage into stopping. Tugh wanted five hundred feet of unoccupied space between the cages when they stopped. His diabolical purpose in that was soon to be disclosed. "700 A. D.," Tugh called. "Yes, Master. I am ready." * * * * * It seemed, as our flight retarded further, that I could distinguish the intervals when in the winter these trees were denuded. There would be naked branches; then, in an instant, blurred and flickering forms of leaves. Sometimes there were brief periods when the gray scene was influenced by winter snows; other times it was tinged by the green of the summers. "750, Migul.... Hah! You know what to do if Harl dares to follow and stop simultaneously?" "Yes, Master." "It will be pleasant to have him dead, eh, Migul?" "Master, very pleasant." "And Tina, too, and that young man marooned in 1777!" Tugh laughed. This meant little to Mary and me; we could not suspect that Larry was the man. "Migul, this is 761." The Robot was at the door. I murmured to Mary to brace herself for the stopping. I saw the dark naked trees and the white of a snow in the winter of 761; the coming spring of 762. And then the alternate flashes of day and night. The now familiar sensations of stopping rushed over us. There was a night seconds long. Then daylight. We stopped in the light of an April day of 762 A. D. There had been a forest fire: so brief a thing we had not noticed it is we passed. The trees were denuded over a widespread area; the naked blackened trunks stood stripped of smaller branches and foliage. I think that the fire had occurred the previous autumn; in the silt of ashes and charred branches with which the ground was strewn, already a new pale-green vegetation was springing up.