After leaving the world of martial arts behind, Hong Siu Lung (Louis Koo), mentor to the Emperor of Qin, enjoys a quiet rural life with his family. This peace is shattered when Ken (Michael Kiu Wai Miu), a man from the future, appears with the intention of altering history, threatening the stability of the Qin Dynasty. The growing crisis forces Siu Lung to return to the center of power to assist his disciple, Ying Ching (Raymond Lam), in confronting a threat that transcends time.

Back to the Past is a sequel to the legendary television series A Step into the Past (2021), adapted from the novel The Chronicles of Searching Qin by Huang Yi. Directed by Yuen Fai Ng and Jack Lai, the film emphasizes high-impact action, featuring Sammo Hung—an iconic Hong Kong cinema legend—as action director. His involvement in designing the fight sequences delivers intense and dynamic action choreography characteristic of Hong Kong cinema. The Indonesian Film Censorship Institution (LSF) has classified this film for audiences aged 13 and above.(ynp)