Inspector Turnbull has arrested a man for murder. The man, an ex-soldier, could not deny he was at the scene of the crime and was found with blood on his face. Turnbull thinks he has the case solved but while taking his prisoner to jail by train the man spots the widow of his old colonel, Hester Prendergast. He pleads with her for help and says he is innocent. Faced with a request she cannot refuse, she embarks on a journey to uncover the truth. Set in 1881, Hester Prendergast travels across England and Scotland to unmask the true killer.