Wong Kei-Ying, a skilled physician and martial artist, resides in Guangzhou during the Qing Dynasty. Dedicated to helping his community, he witnesses the growing influence of opium and corrupt officials led by the malevolent governor, Lei Gong. When Lei Gong poisons Wong's mentor, Master Wu, in a plot to control the local opium trade, Wong pledges to bring justice to his fallen teacher and save his city from the clutches of the drug epidemic. As he delves deeper into this mission, Wong discovers a powerful and deadly martial arts technique, the Shadowless Kick, which requires immense discipline and precision.

In his quest, Wong encounters several challenges, including corrupt officials, ruthless henchmen, and the widespread corruption influenced by Lei Gong's men. Alongside a motley group of allies who rally to his cause, Wong must master the Shadowless Kick technique while maintaining his medical duties. With each confrontation, he sharpens his skills and strengthens his resolve. The conflicts intensify as Wong uncovers deeper layers of betrayal and deceit among those he once trusted. Testing both his martial arts prowess and his moral compass, Wong fights to uphold justice and honor in a tumultuous and dangerous era.