Clea Koshar had been installed in her government office for three days. The notebook in which she had been doing her own work in inverse sub-trigonometric functions had been put away in her desk for exactly fifty-four seconds when she made the first discovery that gave her a permanent place in the history of Toromon's wars as its first military hero. Suddenly she pounded her fist on the computer keys, flung her pencil across the room, muttered, "What the hell is this!" and dialed the military ministry. It took ten minutes to get Tomar. His red-haired face came in on the visiphone, recognized her, and smiled. "Hi," he said. "Hi, yourself," she said. "I just got out those figures you people sent us about the data from the radiation barrier, and those old readings from the time Telphar was destroyed. Tomar, I didn't even have to feed them to the computer. I just looked at them. That radiation was artificially created. Its increment is completely steady. At least on the second derivative. Its build-up pattern is such that there couldn't be more than two simple generators, or one complexed on ..." "Slow down," Tomar said. "What do you mean, generators?" "The radiation barrier, or at least most of it, is artificially maintained. And there are not more than two generators, and possibly one, maintaining it." "How do you generate radiation?" Tomar asked. "I don't know," Clea said. "But somebody has been doing it." "I don't want to knock your genius, but how come nobody else figured it out?" "I just guess nobody thought it was a possibility, or thought of gratuitously taking the second derivative, or bothered to look at them before they fed them into the computers. In twenty minutes I can figure out the location for you." "You do that," he said, "and I'll get the information to whomever it's supposed to get to. You know, this is the first piece of information of import that we've gotten from this whole battery of slide-rule slippers up there. I should have figured it would have probably come from you. Thanks, if we can use it." She blew him a kiss as his face winked out. Then she got out her notebook again. Then minutes later the visiphone crackled at her. She turned to it and tried to get the operator. The operator was not to be gotten. She reached into her desk and got out a small pocket tool kit and was about to attack the housing of the frequency-filterer when the crackling increased and she heard a voice. She put the screw driver down and put the instrument back on the desk. A face flickered onto the screen and then flickered off. The face had dark hair, seemed perhaps familiar. But it was gone before she was sure she had made it out.