Autumn, 1583: Queen Elizabeth's rule is under threat. Plans for an invasion to put Mary Stuart on the throne of England are secretly being laid. And an astrological phenomenon believed to herald the death of one age and the dawn of another has led to frenzied speculation of terrible events to come. Giordano Bruno, the maverick and charismatic agent of Sir Francis Walsingham, spymaster to the queen, has infiltrated the plotters at the French embassy. His mission is to secure the evidence that will allow the execution of Mary Stuart and her cohorts for treason. But his position there is tenuous – while the ambassador trusts him, his beautiful and cunning wife Marie seems determined to prise out his secrets. Meanwhile, the murder of a maid of honour within the palace walls involves Bruno in deeper mysteries. Occult symbols carved into her young flesh point to black magic, but the truth could be even more sinister...