Our nerves must have really been wound tight, because before we knew it we were in the middle of a nasty argument--and it was over nothing, really. But in the middle of it: "Hey, look," Rizzo shouted, pointing to the oscilloscope. The message had stopped. The 'scope showed only the calm, steady line of the star's basic two-day-long pulsation. It suddenly occurred to us that we hadn't slept for more than 36 hours, and we were both exhausted. We forgot the senseless argument. The message was ended. Perhaps there would be another; perhaps not. We had the telescope, spectrometer, photocell, oscilloscope, and computer set to record automatically. We collapsed into our bunks. I suppose I should have had monumental dreams. I didn't. I slept like a dead man. * * * * * When we woke up, the oscilloscope trace was still quiet. "Y'know," Rizzo muttered, "it might just be a fluke ... I mean, maybe the signals don't mean a damned thing. The computer is probably translating nonsense into numbers just because it's built to print out numbers and nothing else." "Not likely," I said. "There are too many coincidences to be explained. We're receiving a message, I'm certain of it. Now we've got to crack the code." As if to reinforce my words, the oscilloscope trace suddenly erupted into the same flickering pattern. The message was being sent again. We went through two weeks of it. The message would run through for seven hours, then stop for seven. We transcribed it on tape 48 times and ran it through the computer constantly. Always the same result--six-digit numbers; millions of them. There were six different seven-hour-long messages, being repeated one after the other, constantly. We forgot the meteorological equipment. We ignored the weekly messages from McMurdo. The rest of the world became a meaningless fiction to us. There was nothing but the confounded, tantalizing, infuriating, enthralling message. The National Emergency, the bomb tests, families, duties--all transcended, all forgotten. We ate when we thought of it and slept when we couldn't keep our eyes open any longer. The message. What was it? What was the key to unlock its meaning? "It's got to be something universal," I told Rizzo. "Something universal ... in the widest sense of the term." He looked up from his desk, which was wedged in between the end of his bunk and the curving dome wall. The desk was littered with printout sheets from the computer, each one of them part of the message. "You've only said that a half-million times in the past couple weeks. What the hell is universal? If you can figure that out, you're damned good." _What is universal?_ I wondered. _You're an astronomer. You look out at the universe. What do you see?_ I thought about it. _What do I see? Stars, gas, dust clouds, planets ... what's universal about them? What do they all have that_.... "Atoms!" I blurted. Rizzo cocked a weary eye at me. "Atoms?"