The protagonist is the sharp-witted Dr. Peter Blood, a fictional Irish physician who had had a wide-ranging career as a soldier and sailor (including a commission as a captain under the Dutch admiral De Ruyter) before settling down to practice medicine in the town of Bridgwater in Somerset. The book opens with him attending to his geraniums while the town prepares to fight for the Duke of Monmouth. He wants no part in the rebellion, but while attending to some of the rebels wounded at the Battle