"You needn't mention this to anyone till we get back to the Earth," said Dr. Perkins, sawing the sample in two. "I wouldn't want to appear insubordinate. Now, let's see, we'll leave the spectroscope test out--that was made on the other sample." He sliced off a shaving, set it on the viewing table and adjusted the light. "That's odd," he remarked after a moment. "There's no sign of the air bubbles Reuter found in the other sample." One of the other fragments he dropped into a crucible, set the dial at 900 degrees and flicked on the little motor that would melt it by atomic power heat. Adam watched breathlessly as the oven was opened, the little molten globe of silvery metal quenched in acid, then dropped into an open-ended pipette and the container filled with liquid. "The difference between what that pipette held and what it should hold," explained Dr. Perkins as he adjusted a scale to weigh the liquid, which had been poured off, "will be the displacement of the sample. See--2.4 cubic centimeters. Now the weight. We read it directly by putting the displaced weight in water on one arm of the scale and the sample of metal on the other. Now, when they balance the pointer--my God! Longworth!" There was a ghost of a smile around Adam's mouth; Paulette gripped his arm. "Yes?" "Longworth, the specific gravity is 1.93! This is more than important, it's vital! I'm going to call in my assistant and make that test over again, spectroscope and all. This is no isotope. This is perfectly genuine beryllium. How could Reuter have made such an error!" Adam and Paulette left the chemist feverishly ringing for his assistant. * * * * * "I tell you, Walter, I don't like it. We've got to get out of here." Professor Reuter's usually smooth voice had an edge of worry and his fat face was haggard. "What's the matter, losing your nerve?" taunted Captain McCausland. The professor slapped the table of the cabin to which they had returned from their visit to the subsoil of Pluto. "I tell you, Walter, I'm risking everything by going on. My own men are wondering about that fluorine fiasco, and Perkins was just able to swallow my analysis of the beryllium and no more. I have a scientific reputation to keep up, you want to remember; it won't do me any good to succeed if I go back with my reputation for accuracy in tatters." "Reputation!" McCausland's voice was mocking. "Just like a school girl, afraid to be caught out with the boys. Why, you old goat, if anything went wrong now, do you suppose anyone would blame me? No, they wouldn't. I only acted on the advice of my head of science. You're in this right up to the neck, Reuter, reputation or no reputation, and now you're going to see it through--on the lines I mark out for you." The professor's weak anger collapsed. "Now, now, Walter, don't be angry. I had no intention of falling down on you. But it seems to me that I'm taking a good deal of the risk, while you--"