雷蔵の死により12作に及んだ“眠狂四郎“シリーズは終了したが、その3ヵ月後、早くも松方弘樹主演によって復活した。ベテラン監督・森一生も“狂四郎“シリーズは初めての演出。将軍・家斉の世継ぎ・家慶になりすました双子の弟の、陰謀に巻き込まれる狂四郎の活躍を描く。
Bill Saunders, disturbed ex-soldier, kills a man in a postwar London pub brawl. Fleeing, he hides out in the apartment of lonely nurse Jane Wharton. Later, despite misgivings about his violent nature, Jane becomes involved with Bill, who resolves to reform. She gets him a job driving a medical supplies truck. But racketeer Harry Carter, who witnessed the killing, wants to use Bill's talents for crime.