On Sado Island, the governor’s son has been arrested for the murder of the exiled Prince Okisada. The court wants Sugawara Akitada to investigate the case unofficially. In the most dangerous undertaking of his career, Akitada poses as a prisoner to uncover the truth and perhaps even greater treachery. When he runs into trouble and disappears, his faithful retainer Tora sets out to find him. Between them, they overcome brutal enemies and solve an ingenious crime that had nearly toppled an emperor.