December 1585: The last of his line, King Henry III of France has appointed a Protestant as his successor, leaving him in fear of a coup being orchestrated by the Catholic League. In this follow-up to book five, Treachery, ex-monk and spy Giordano Bruno is asked by the king to investigate several mysterious deaths linked to a plot. When Bruno is implicated in the death of Leonie, a member of the Queen Mother's "Flying Squadron," he is forced to call on English Catholic assassin Charles Paget and his connections for help—and finds that it comes with a price, involving an old enemy.