It is 1605. James I, the Catholic son of Mary, Queen of Scots has been king for two years. His Catholic supporters are disappointed as life has not become easier for them. Religious persecution continues: non-attendance at Protestant services incurs heavy fines, while priests are tortured and exiled. Robert Catesby, a Catholic aristocrat is disillusioned. Gathering about him a band of similar-minded Catholics, he intends to change the situation by blowing up the Parliament, the king and all his entourage. Catesby asks Guy Fawkes, a Catholic soldier to help them. Today we know that the plot failed, but had this band already been infiltrated by Sir Robert Cecil, James I's devious Secretary of State? Who sent the warning note that a "terrible blow" was imminent? What would have happened had this desperate plot succeeded? David L. Young's well-researched novel tries to answer these questions.