The object arrived without warning, tearing a spiral path of devastation across the rural landscape. After the explosion, searchers sifted through the immense pile of debris ... to discover a fantastically instrumented capsule, and a strangely human pilot, stone dead. Bowden Karvel's theory, that the capsule's port of origin lay in the distant future, seemed a plausible explanation. But while investigating, the capsule was accidentally dispatched again through time ... only to reappear with an alien navigator, this time destroying a small French town. One thing seemed imperative: a human operator must man the intricate controls of the capsule, riding it forward to its mysterious point of origin. And Bowden Karvel seemed the perfect choice to make the trip.