The Doctor, Ben, Polly and Jamie land on a lunar weather-control base in 2070, where the Gravitron that steadies Earth's climate is under threat from an illness sweeping through the crew. As colleagues collapse and die in ways the base commander can't explain, the Doctor has less than a day to find a cause before the base is evacuated. Feverish and delirious, Jamie speaks of a ghostly Phantom Piper out of his family's Highland lore, though what is stalking the corridors proves rather less supernatural. Gerry Davis's 1974 novelisation of the Second Doctor serial The Moonbase, an early Cyberman story for the Target range.
Summary by Loreful, from public sources