The schizoid Earth

Lethbridge-Stewart was supposed to be in the mountains of the east, but things didn't quite go according to plan. On the eve of war, something appeared in the sky; a presence that blotted out the moon. Plagued by nightmares of being trapped in a past that never happened, Lethbridge-Stewart must unravel the mystery of a man ten years out of his time; a man who cannot possibly exist.