The scene is London in 1399. The strangest and most interesting king in English history, Richard II, is on the throne. Over the past several years his reign has been troubled by peculiar signs and portents, and as the turn of the century approaches, there is talk of an apocalypse. Meanwhile a mad nun, who was born beneath the convent of Clerkenwell, is visited by visions of the future. As Sister Clarice's prophecies signal the beginning of dark days of reckoning and retribution, a mystery soon unfolds that involves a secret sect called the Predestined Men, who are plotting to overthrow the established Church, dethrone Richard, and set off explosions in churches in five parts of London; a double-crossing conspirator; and Sister Clarice herself