In the third adventure of the Blue Satan Mystery series, Mrs. Kean and the earl-turned-highwayman Blue Satan solve a murder against a backdrop of espionage and treason. In the fall of 1715, supporters of the Pretender James Stuart launch a revolution that threatens to overthrow George I. As a result, all Roman Catholics have been banished from the city of London and freedom of speech is greatly restricted. Accused of printing seditious pamphlets, Mrs. Kean's brother Jeremy has been sent to Newgate prison, where he soon finds himself charged with murder. Steadfastly maintaining his innocence, Jeremy turns to the duo to help save his life. However, Mrs. Kean and Blue Satan can only uncover the motive that reveals the killer by first understanding the murderous deed.