Yu Wenchuan, a young man who grew up in the shadow of his father's death, walked Hong Kong, a land full of danger and betrayal, with his obsession for the truth. Next to him, Robert Ann, the former brother, is now full of unknown mysteries. They will face a cruel fate, challenge the forces of darkness, and uncover countless mysteries hidden deep in the corners of the city. But as one crisis breaks out, they find that they can no longer control their own destiny. The death of their father and the ulterior secret seem to be pushing them step by step into the abyss. In this city without rules, survival is the only option. 'Undercurrent', an ultimate battle about fate, betrayal and death, is quietly taking place.
Concept: Detective suspense, modern martial arts