"They will be cut off from the main herd," the optimistic reports announced. "We shall deal with the main herd first. This year the sacrifice will have to be made, but it will be the last. Scientists have at last hit upon an infallible toxin which will utterly destroy this menace within a few months." Nobody believed that story, for everything had been tried and failed. In their laboratory Cliff and Kay were working frantically. And now the coldness that had developed between them was affecting their collaboration too. Cliff was keeping something back from Kay. * * * * * Kay knew it. Cliff had made some discovery that he was not sharing with his partner. Often Kay, entering the laboratory, would find Cliff furtively attempting to conceal some operation that he was in the midst of. Kay said nothing, but a brooding anger began to fill his heart. So Cliff was trying to get all the credit for the result of their years of work together! And always, in the back of his mind, there was a vision of the little Government ticket in Ruth's hand, with the numbers in staring black type. They had burned into his brain. He could never forget them. Often at night, after a hard day's work, he would suddenly awaken out of a hideous nightmare, in which he saw Ruth taken away by the agents of the Government, to be thrown as a sacrifice to the monsters. And Cliff was hiding something! That made the situation unbearable. The coolness between the two men was rapidly changing into open animosity. And then one day, quite by chance, in Cliff's absence, Kay came upon evidence of Cliff's activities. Cliff was no longer experimenting with the W-ray! He was using a new type of ray altogether, the next series, the psenium electron emanation discovered only a few years before, which had the peculiar property of non-alternation, even when the psenium electron changed its orbit around the central nucleus of the psenium atom. Instead of discontinuity, the psenium electron had been found to emit radiation steadily, and this had upset the classic theories of matter for the ninth time in the past fifteen years. * * * * * And Kay's wrath broke loose in a storm of reproaches when Cliff came into the laboratory. "You've been deliberately keeping me in the dark!" he shouted. "You're a nice sort of partner to have! Here's where we split up the combination, Hynes!" "I've been thinking that for a long time," sneered Cliff. "The fact is, Kay, you're a little too elementary in your ideas to suit me. It's due to you that I kept hammering away on the wrong tack for years. The sooner we part, the better."