A brother's wrongful imprisonment for murder forces Mrs. Kean and the notorious highwayman Blue Satan to unravel a conspiracy during a politically turbulent era. In the autumn of 1715, London is gripped by the Jacobite rising, a revolution threatening to depose King George I. Amidst widespread suspicion and restricted freedoms, Mrs. Kean's brother, Jeremy, is imprisoned in Newgate and accused of printing seditious pamphlets, only to be further implicated in a murder. To save him, Mrs. Kean and Blue Satan must navigate a dangerous landscape of treason and espionage, piecing together the motive behind the crime to expose the true killer.

The third installment in the Blue Satan Mystery series, 'The Motive from the Deed' continues to blend historical intrigue with romantic elements. The narrative is driven by the urgency of saving a wrongly accused brother, set against the volatile political landscape of 1715 London. Readers can expect a complex plot involving espionage, treason, and the unraveling of a murder mystery. The dynamic between Mrs. Kean and Blue Satan provides a consistent draw for fans of the series, offering both suspense and a touch of romantic tension.