That inhumanly powerful mind at last began to weaken, but it became entirely quiescent only after the administration of the seventh milligram of that direly potent drug.

"Just as well that I allowed only six hours." DuQuesne sighed in relief as he began to explore the labyrinthine intricacies of the frightful brain now open to his gaze. "I don't see how any possible form of life can hold together long under seven milligrams of that stuff."

He fell silent and for more than an hour he studied the brain of the engineer, concentrating upon the several small portions which contained knowledge of most immediate concern. Then he removed the headsets.

"His plans were all made," he informed Loring coldly, "and so are mine, now. Bring out two full outfits of clothing—one of yours and one of mine. Two guns, belts, and so on. Break out a bale of waste, the emergency candles, and all that sort of stuff you can find."

DuQuesne turned to the Fenachrone, who stood utterly lax, inanimate, and stared deep into those now dull and expressionless eyes.

"You," he directed crisply, "will build at once, as quickly as you can, two dummies which will look exactly like Loring and myself. They must be lifelike in every particular, with faces capable of expressing the emotions of surprise and of anger, and with right arms able to draw weapons upon signal—my signal. Also upon signal their heads and bodies will turn, they will leap toward the center of the room, and they will make certain noises and utter certain words, the records of which I shall prepare. Go to it!"

"Don't you need to control him through the headsets?" asked Loring curiously.

"I may have to control him in detail when we come to the really fine work, later on," DuQuesne replied absently. "This is more or less in the nature of an experiment, to find out whether I have him thoroughly under control. During the last act he'll have to do exactly what I shall have told him to do, without supervision, and I want to be absolutely certain that he will do it without a slip."

"What's the plan—or maybe it's something that is none of my business?"

"No; you ought to know it, and I've got time to tell you about it now. Nothing material can possibly approach the planet of the Fenachrone without being seen, as it is completely surrounded by never less than two full-sphere detector screens; and to make assurance doubly sure our engineer there has installed a mechanism which, at the first touch of the outer screen, will shoot a warning along at tight communicator beam, directly into the receiver of the nearest Fenachrone scout ship. As you already know, the smallest of those scouts can burn this ship out of the ether in less than a second."