As the _Vortex Blaster II_ began settling into position, the two scientists took their places. Cloud was apparently his usual self-controlled self, but Joan was white and strained—almost shaking. He sent her a steadying thought, but her block was up, solid. “Don’t take it so hard, Joanie,” he said, soberly. “Margie’ll take ’em, I hope—but even if she doesn’t, there’s a dozen things not tried yet.” “That’s just the trouble—there _aren’t_! We put just about everything we had into Lulu; Margie is only a few milliseconds better. _Perhaps_ there are a dozen things not tried yet, but I haven’t the faintest, foggiest smidgeon of an idea of what any of them could be. Margie is the last word, Storm—the best analogue computer it is possible to build with today’s knowledge.” “And I haven’t been a lick of help. I wish I could be, Joan.” “I don’t see how you can be. . . . Oh, excuse me, Storm, I didn’t mean that half the way it sounds. Do you want to check the circuitry? I’ll send for the prints.” “No, I couldn’t even carry your water-bottle on that part of the job. I’ve got just a sort of a dim, half-baked idea that there’s a possibility that maybe I haven’t been giving you and your brains a square deal. By studying the graphs of the next three or four tests maybe I can find out whether. . . .” “Lieutenant-Commander Janowick, we are in position,” a crisp voice came from the speaker. “You may take over when ready, madam.” “Thank you, sir.” Joan flipped a switch and Margie took control of the ship and its armament—subject only to Cloud’s overriding right to fire at will. “Just a minute, Storm,” Joan said then. “Unfinished business. Whether what?” “Whether there’s anything I can do—or fail to do—that might help; but I’ve got to have a lot more data.” Cloud turned to his chart, Joan to hers; and nothing happened until Cloud blew out the vortex himself. The same lack of something happened in the case of the next vortex, and also the next. Then, as the instruments began working in earnest on the fourth, Cloud reviewed in his mind the figures of the three previous trials. On the first vortex, a big toughie, Margie had been two hundred fifty milliseconds short. On the second, a fairly small one, she had come up to seventy-five. On Number Three, middle-sized, the lag had been one twenty-five. That made sense. Lag was proportional to activity and it was just too bad for Margie. And just too _damn_ bad for Joanie—the poor kid was just about to blow her stack. . . . But wait a minute! What’s this? This number four’s a little bit of a new one, about as small as they ever come. Margie ought to be taking it, if she’s ever going to take anything . . . but she isn’t! She’s running damn near three hundred mils behind! Why? Oh—amplitudes—frequencies extreme instability. . . . Lag isn’t proportional _only_ to activity, then, but jointly to activity and to instability.