5th November 1609. It is four years to the day since Catholic conspirators tried to blow up James I and his Parliament with bloody consequences to themselves and their supporters. Ned Warriner is a known Catholic sympathiser, yet he has secretly returned to England to search for the woman he loves, Kate Revill. Another year of exile on the Continent without her is unthinkable. If Ned is discovered he faces execution.
But fate has an even more curious twist in store for him. Within hours of disembarking in London he has stumbled upon a mysterious letter written by the Elizabethan magus John Dee to one of his acolytes. In it is the greatest secret of the world: instructions on how to transmute base material into gold. It is also a secret that people will kill for: whoever touches the letter or speaks of it will die. Its ownership will take Ned right to the corrupted heart of the plot-riven kingdom.