"Holmes," said Burke reflectively. "I think I've got what we want. You know how artificial gravity's made, what the circuit is like." To anybody but Holmes and Keller, the comment would have seemed idiotic. It would have seemed insane even to them, not too long before. But Holmes nodded. "Yes. Of course. Why?" "There's a chooser-circuit in the globes," said Burke carefully, "that picks up radiation from an Enemy ship, and multiplies it enormously and beams it back. The circuit that made the radiation to begin with has to be resonant to it, as the globe burns it out while dashing down its own beam." "Naturally," said Holmes. "What about it?" "The point is," said Burke, "that one _could_ treat a suddenly increasing gravity-field as radiation. Not a stationary one, of course. But one that increased, fast. Like the gravity-fields of the Enemy ships, moving faster than light toward our sun." "Hmmmm," said Holmes. "Yes. That could be done. But hitting something that's traveling faster than light--" "They're traveling in a straight line," said Burke, "except for orbiting around each other every few hours. There's no faster-than-light angular velocity; just straight-line velocity. And with the artificial mass they've got, they couldn't conceivably dodge. If we got some globes tricked up to throw a beam of gravity-field back at the Enemy ships, there might be resonance, and there's a chance that one might hit, too." Holmes considered. "It might take half an hour to change the circuit," he observed. "Maybe less. There'd be no way in the world to test them. But they might work. We'd want a lot of them on the job, though, to give the idea a fair chance." Burke stood up, creaking a little from long immobility. "Let's hunt for the way back to the fortress," he said. "There is a way. At least two crazy birds were marching around in the fortress' corridors." Holmes nodded again. They began a search. Matter transposed from the fortress--specifically, the five of them--came out in a nearly three-walled alcove in the side of what had once been a magnificent building. Now it was filled with the trunks and stalks of trees and vines which grew out of every window-opening. There were other, similar alcoves, as if other matter-transposers to other outposts or other worlds had been centered here. They were looking for one that a plump, ridiculous bird might blunder into among the broken stones. They found a metal plate partly arched-over by fallen stones in the very next alcove. They hauled at the tumbled rock. Presently the way was clear. "Come along!" called Burke. "We've got a job to do! You girls want to fix breakfast and we want to get to work. We've a few hundred light-years to cross before we can have our coffee."