England, 1688 King James II finally has an heir – but not all are rejoicing. Protestant bishops have been sent to the tower, strange symbols are appearing on the streets of London and rumblings of dissent are whispered throughout the city. Amidst the turmoil, Secretary James Marwood has been living a quiet life.

But his peace is broken when a figure from the past emerges with a dangerous proposition. Change is coming, and Marwood needs an ally if he is to retain his position at Whitehall. So, reluctantly, he agrees to investigate an apparent suicide.

The man’s death is soon revealed to be a murder, and his past yields suspicious connections. Violence begins to erupt around the city, protestants raging against a Catholic king, and the atmosphere at court grows tense. Marwood’s investigation leads him to uncover a deadly and treasonous conspiracy, one that threatens the crown and the stability of the nation.