A highly skilled bomb disposal expert is tasked with dismantling bombs and curbing dangerous terrorist threats in Hong Kong. The protagonist, Cheung, faces a formidable adversary in the form of a vengeful criminal mastermind who orchestrates a series of bombings across the city. Having initially failed to capture him during a previous operation, Cheung is now driven by both professional duty and personal vendetta. The stakes are raised when the villain takes control of the Cross-Harbour Tunnel, one of the busiest in the city, threatening massive destruction and loss of life. The situation forces Cheung to confront his deepest fears and employ every ounce of his expertise to devise a countermeasure.

As the tense standoff unfolds, Cheung faces overwhelming challenges that test his resolve, courage, and skills in high-stakes bomb defusal and crisis management. With the clock ticking, he navigates a series of intricate traps and puzzles laid out by the criminal mastermind, while also managing the safety of hostages and civilians trapped in the tunnel. Battles of wits ensue between Cheung and his relentless adversary, as every second counts towards preventing a disastrous outcome. The narrative builds to an intense climax amid the high-pressure environment beneath the bustling city streets.