He had plenty of time, during the six-day return journey, to read and re-read Cavour's final words and to make photographic copies of the withered old pages.
The trip to Venus had been easy for old Cavour; he had landed precisely on schedule, and established housekeeping for himself in the cave. But, as his diary detailed it, he felt strength ebbing away with each passing day.
He was past eighty, no age for a man to come alone to a strange planet. There remained just minor finishing to be done on his pioneering ship—but he did not have the strength to do the work. Climbing the catwalk of the ship, soldering, testing—now, with his opportunity before him, he could not attain his goal.
He made several feeble attempts to finish the job, and on the last of them fell from his crude rigging and fractured his hip. He had managed to crawl back inside the cave, but, alone, with no one to tend him, he knew he had nothing to hope for.
It was impossible for him to complete his ship. All his dreams were ended. His equations and his blueprints would die with him.
In his last day he came to a new realization: nowhere had he left a complete record of the mechanics of his spacewarp generator, the key mechanism without which hyperspace drive was unattainable. So, racing against encroaching death, James Hudson Cavour turned to a new page in his diary, headed it, in firm, forceful letters, For Those Who Follow After, and inked in a clear and concise explanation of his work.
It was all there, Alan thought exultantly: the diagrams, the specifications, the equations. It would be possible to build the ship from Cavour's notes.
The final page of the diary had evidently been Cavour's dying thoughts. In a handwriting increasingly ragged and untidy, Cavour had indited a paragraph forgiving the world for its scorn, hoping that some day mankind would indeed have easy access to the stars. The paragraph ended in midsentence. It was, thought Alan, a moving testament from a great human being.
The days went by, and the green disk of Earth appeared in the viewscreen. Late on the sixth day the Cavour sliced into Earth's atmosphere, and Alan threw it into the landing orbit he had computed that afternoon. The ship swung in great spirals around Earth, drawing ever closer, and finally began to home in on the spaceport.