In 2006, senior business consultant Vincent Wai and his apprentice Max Hong get taken hostage during a business trip to Vietnam. While Max manages to escape imprisonment, Vincent stays confined in a deserted island for a decade.

Ten years later, Vincent is found and taken back to Hong Kong, where he learns that he was legally declared dead. Struggling to understand the reasons behind his abduction, Vincent visits Vietnam again to probe into the matter, bringing along his wife Cathy Yuen and his good friend Lam Ho Yan. Local police, however, constantly obstructs their investigation, throwing the trio into dangerous situations.

Upon their return to Hong Kong, Vincent learns that Cathy had remarried during his disappearance and that her current husband is Ho-yan. Broken-hearted, Vincent chooses to leave Cathy and their son and plunges his own life into his work. With Max's support, Vincent finds his place at work again and even gets involved in an ambiguous relationship with his boss, Queenie Yip. But Vincent still feels lost. Recalling his disappearance with indignation, he launches another investigation. The unexpected clues he discovers lead him on a journey of vengeance.