"There is nothing to be done," the Cyberene said dully. "I have checked in that other time stream. There is still positive record that the Brain was not activated."
"Maybe it takes time for the momentum of events to force the change," Earl suggested.
Didn't the Cyberene suspect yet? Didn't it realize?
"No," the Cyberene said dully. "I have failed. More, I have re-checked the mathematical basis of the theoretical picture, and think I know where I erred. The cause of the split that created two Earths, travelling close together down through so many centuries, could not have been something occurring in the original time stream. It took something applied from the fifth dimension—and in the neighborhood of the split that could only have been one thing, the force with which the time tube hooked onto 1980. It had to be that. The accident. I didn't take it into account."
"That's what I've thought all along," Earl said quietly.
"At that instant," the Cyberene went on as though it hadn't heard him, "the split occurred. You became two Earl Fryes, to mention one facet of the split. One of you went its way, making an accurate report of its experiments, creating me eventually—"
While the Cyberene talked, the desolate scene vanished, and the glass cage lifted upward slowly, as though it were a curtain, lifting for the final scene.
The twin lenses of the Cyberene's video eyes were fixed on them, alive with an intelligence that was inhuman.
"No," Earl said. "That one of me discovered the identity of the nerve substance, but suppressed it."
"That couldn't be," the Cyberene objected. "Nothing appeared in its life to cause it to do that. You were the one who had the data to make such a decision."