A remote area of the Scottish Highlands has been cordoned off and is being guarded by an army of I.R.A. mercenaries and ex-Nazi thugs. Local rumour has it that eccentric laird James Fraser Clyde is looking for buried treasure, but the British government fears he might be building an atomic bomb in an attempt to win Scottish independence. Yet the truth may be something far worse: a mysterious contagion is turning the locals into deformed, grunting creatures, with a single-minded urge to kill and spread their infection. Sir Marcus Levin, the Nobel Prize-winning bacteriologist, must find a way to halt the epidemic before it gets out of hand and destroys the world. But what is causing it? Who started it, and why? And can it be stopped?