* * * * * When he had awakened from his first period of natural slumber, he had received a terrible shock. His left arm was gone, amputated at the shoulder. Strangely, the wound had healed while he slept, probably the result of the Venerian doctoring, so there was no pain: but the shock had been terrible. After he had recovered from the effects of that shock, he had resolved to make the Venerians pay for what they had done. And then he had realized that the inhuman brutes must be destroyed for a greater reason: unless he interfered, he believed that they would carry out their intention of destroying all human life. As the weeks passed by, while strength was returning to Parkinson, he learned in a general way what the invaders were doing. They were engaged in developing vast quantities of microbes to be spread over Earth. When these were ready, a great amount of fine dust that the Venerians had brought with them, was impregnated with the bacilli. This was then taken up into the tower, where, as Parkinson learned later, it was blown out through the four tubes that spun around the tower's top, to drift through the air--to enter human bodies--to destroy life. The Venerians worked with the cultures and impregnated dust without protection of any sort: evidently they were immune to the disease. Later Parkinson learned that he was likewise immune; they had rendered him so after trying the germs upon him. Gradually the bacteriologist's health returned--so gradually that his captors seemed not to notice it. He was glad of this, for their vigilance had relaxed, and he did not want it renewed. Even when he was as strong and well as ever, he spent much time in bed, shamming illness. And when he could do so without danger of detection, he kept a close watch upon the three, waiting for a time when he would be entirely alone. * * * * * At last his opportunity came. The three Venerians rose to the surface together, leaving him in his room, to all outward appearances, asleep. But sleep was far from him at that moment; he had been watching. Shortly after the sphere had vanished up the shaft, Parkinson emerged from his room. For a moment he surveyed the circle of doors: then he shrugged his shoulders. They all looked alike to him. Quickly he crossed the room, and pressed a button that mechanically opened a door. It was his purpose, first of all, to secure a weapon; one room would do as well as another for a beginning. At first glance Parkinson was struck by the strange familiarity of this chamber: then, after a moment, he recognized it. A tall, high-backed metal chair in its center was its mark of identification. This was the chamber wherein the Venerians had transferred a record of his knowledge to their minds. Carefully he looked around in search of a weapon, but the room held nothing but the chair and the thought transference device. In a moment he withdrew, closing the door behind him.