"I tell you - we will cut off this King's head. Aye, with the crown on it!"
It is December 1648. Although victorious over the Cavaliers in the Civil Wars, the Roundheads are struggling to retain power. Plans are afoot to spirit King Charles from his prison, and the Doctor and his companions become embroiled in the intrigue...
Ben finds himself press-ganged and on board a mysterious ship to Amsterdam. Polly is an unwitting accomplice in the plot to rescue the King, and the Doctor and Jamie find themselves arrested and imprisoned in the Tower of London under suspicion of conspiracy.
Can the Doctor and Jamie escape, manage to find Ben and Polly and still ensure that history remains on its proper course?