Camhorn grinned. "People. Until it's deliberately tampered with, Ymir is changeless—as far as we know. Furthermore it will, in compound, extend its inhibiting field effect instantaneously to three other elements of the same series. A very fortunate circumstance, because Ymir has been found only in minute amounts, and unknown factors still prevent its artificial production. The other three elements are produced readily, and since a very small proportion of Ymir retains them in stable—or pseudostable—form, they can be conserved indefinitely."
"That's the Ym-400 compound?" Fry asked.
"That's it."
Fry said thoughtfully, "Perhaps I should remind you, Howard, that this conversation is being recorded."
Camhorn nodded. "That's all right. Now that we know someone else is in possession of sixty-eight kilograms of Ym-400, we're confronted with radically altered circumstances. The loss incurred by the theft isn't important in itself. The Ymir component in such a quantity is detectable almost only by its effects, and the other components can be produced at will.
"The question is how much the people who have the stolen compound in their hands actually know about it. We would prefer them to know several things. For example, up to a point Ym-400 is easily handled. It's a comparatively simple operation to reduce or restore the force field effect. The result is a controlled flow of radioactivity from the compound, or its cessation. Now, you've mentioned having heard that Ym-400 transmutes space-time stresses—"
Fry nodded.
"Well," Camhorn said, "as a matter of fact, that's exactly what it appears to do—as was surmised originally of the unstable elements in the series. The active compound transmutes space-time stresses into a new energy with theoretically predictable properties. Theoretically, for example, this new energy should again be completely controllable. Have you picked up any rumors of what our experiments with the substance were supposed to achieve?"
Fry said, "Yes. I forgot that. I've heard two alternate theories. One is that the end result will be an explosive of almost unimaginable violence. The other is that you're working to obtain a matter transmitter—possibly one with an interstellar range."