The Savage Dawn — Peter Williams

In the remote hills of Wales, Matt Campbell finds himself the reluctant leader of a small band of refugees who are mentally unaffected by a recent apocalyptic disaster. Among them, an old priest is suffering strange dreams involving an ancient artefact he carries - a golden chalice recovered from his church. Meanwhile Arthur Wiseman, a delusional psychopath with the ability to perceive the thoughts of others, is also unscathed by the disaster and soon discovers that that a strange mental affliction has left survivors vulnerable to his powerful mind. When Arthur learns of the existence of a magical chalice in distant Wales, he becomes convinced that he is the reincarnation of King Arthur and builds an army of savages to seek out and claim what he believes must surely be the mythical Holy Grail.