words created out of my imagination. Like the rest of you, I knew nothing of the true action of the booster. It was only gradually that truth dawned on me. But by the time we had made our first 'landing' I had guessed. That was why I demanded we always take organic surveyor readings. I knew we had traveled far into future time, far beyond the life period of man on Earth. But I wasn't sure how far we had gone, and I lived with the hope that Klae's booster might reverse itself and start carrying us backwards down the centuries."

For a long time I stood there in silence, a thousand mad speculations racing through my mind.

"How about that piece of Indurate?" I said at length. "It was chipped off an image in the ruins of a great building a mile or so from here."

"An image?" repeated Norris. A faint glow of interest slowly rose in his eyes. Then it died. "I don't know," he said. "It would seem to presuppose that the formula, both parts of it, was known by Klae and that he left it for posterity to discover."

All this time Mason had been standing there, eyes smouldering, lips an ugly line. Now abruptly he took a step forward.

"I've wanted to return this for a long time," he said.

He doubled back his arm and brought his fist smashing onto Norris' jaw. The Navigator's head snapped backward; he gave a low groan and slumped to the floor.

And that is where, by all logic, this tale should end. But, as you may have guessed, there is an anticlimax—what story-tellers call a happy conclusion.

Mason, Brandt, and I worked, and worked alone, on the theory that the secret of the Indurate formula would be the answer to our return down the time trail. We removed the body of Ganeth-Klae from its solidifex envelope and treated it with every chemical process we knew. By sheer luck the fortieth trial worked. A paste of carbo-genethon mixed with the crushed seeds of the Martian iron-flower was spread over Klae's chest and abdomen.

And there, in easily decipherable code, was not only the formula, but the working principles of the ship's booster—or rather, time-catapult. After that, it was a simple matter to reverse the principle and throw us backward in the time stream.

We are heading back as I write these lines. If they reach print and you read them, it will mean our escape was successful and that we returned to our proper slot in the epilogue of human events.

There remains, however, one matter to trouble me. Navigator Norris. I like the man. I like him tremendously, in spite of his cold-blooded confession, and past record. He must be punished, of course. But I, for one, would hate to see him given the death penalty. It is a serious problem.