"To look at this," he admitted, "you'd think the sun was going out. Of course it can't be," he added hastily. "Not possibly. But there is an extraordinary number of sunspots. Maybe they'll clear. But meanwhile the amount of heat reaching us is dropping. As far as I know there's no parallel for it. Night temperatures are thirty degrees lower than they should be. Not only here, either, but at all the robot weather-stations that have been spotted around the planet. They average forty below zero minimum, instead of ten. And--there is that terrific lot of sunspots...." Bordman frowned. Sunspots are things about which nothing can be done. Yet the habitability of a border-line planet, anyhow, could very well depend on them. An infinitesimal change in sun-heat can make a serious change in any planet's temperature. In the books, the ancient mother planet Earth was said to have entered glacial periods through a drop of only three degrees in the planet-wide temperature, and to have been tropic almost to its poles from a rise of only six. It had been guessed that those changes on the planet where humanity began had been caused by a coincidence of sunspot maxima. Lani III was already glacial to its equator. Sunspots could account for worsening conditions here, perhaps. _That message from the inner planet could be bad_, thought Bordman, _if the solar constant drops and stays down awhile._ But aloud he said: "There couldn't be a really significant permanent change. Not quickly, anyhow. Lani's a sol-type star, and they aren't variables, though of course any dynamic system like a sun will have cyclic modifications of one sort or another. But they usually cancel out." He sounded encouraging, even to himself. There was a stirring behind him; Riki Herndon had come silently into her brother's office. She looked pale. She put some papers down on the desk. "That's true," she said. "But while cycles sometimes cancel, sometimes they enhance each other. They heterodyne. That's what's happening." Bordman scrambled to his feet, flushing. Herndon said sharply: "What? Where'd you get that stuff, Riki?" She nodded at the sheaf of papers she'd just laid down. "That's the news from home." She nodded again, to Bordman. "You were right. It was the same message, repeated over and over. And I decoded it like children decode each other's secret messages. I did that to Ken once. He was twelve, and I decoded his diary, and I remember how angry he was that I'd found out he didn't have any secrets." She tried to smile. But Herndon wasn't listening. He read swiftly. Bordman saw that the under sheets were rows of dots and dashes, painstakingly transcribed and then decoded. There were letters under each group of marks. Herndon was very white when he'd finished. He handed the sheet to Bordman. Riki's handwriting was precise and clear. Bordman read: