Back to the Qin Dynasty (Cantonese)

From the 21st century, Xiang Shaolong (Louis Koo) once traveled through time and helped the King of Qin (Raymond Lam) unify the realm. This fateful entanglement across time binds them together, forging a bond of mentor and friend. However, years after Xiang Shaolong retires to a pastoral life, an unknown time-traveler suddenly appears, plunging the great empire into crisis. The King of Qin is forced to seek help from the reclusive Xiang Shaolong. Facing a formidable enemy capable of rewriting history, can they set aside their differences and unite against the threat? Will the bond of mentorship, loyalty, and gratitude become their armor, or a blade turned against each other?