Vincent Ma [Edan Lui] sells a frankenwatch—an antique piece assembled from vintage parts sourced from different watches—at his father’s shop. Uncle [Keung To], the son of a powerful underworld watch dealer, recognizes Vincent’s talent and wants to recruit him as the go‑to watchmaker for a heist crew. Initially, Vincent refuses, but Uncle’s threats to reveal his deception to his father’s customers push him to accept. Uncle then introduces Vincent to the crew’s leader, Chief [Louis Cheung], and orders Chief to assemble Mario [Michael Ning] and Ms. Hong [Luna Shaw] for a mission to steal three Picasso watches in Japan. Mario hesitates, while Ms. Hong lashes out in rage, and Yoh [Anson Lo], Ms. Hong’s son, volunteers to join in hopes of earning money for his mother’s cataract surgery.
The crew tracks down the Picasso watches to a renowned Tokyo watch store. They gain access to the VIP room by posing as wealthy buyers who intend to purchase an expensive timepiece from Chief and Mario. Vincent becomes distracted, though, by the legendary Moonwatch locked in the vault, and momentum almost slips away. Mario cautions Vincent to take only the three watches they need. The heist unfolds during a fireworks show, and the crew penetrates the VIP room. Yoh initially struggles to unlock the vault, but Vincent notices dried wax on the buttons, a tell that helps Yoh open it. A drunk pedestrian triggers the alarm at the storefront, forcing a risky retreat. In a moment of greed, Mario seizes the Moonwatch during the escape. Later, he learns the Moonwatch’s backstory and realizes the trouble he’s in with Uncle, and he uses Vincent’s phone to expose the crew’s ties to Uncle within the underground watch‑dealing world. Chairman Kato [Kazuya Tanabe] orders his men to retrieve the Moonwatch, escalating the stakes. Chief confronts Mario about an additional watch demanded by the Japanese hitmen, and Mario shows him the stolen Moonwatch, proposing a revolt against Uncle to protect his father’s longtime associates. The crew, now wary of Uncle’s grip, resolves to expose him and secure their own safety.
Yoh pretends to betray the crew and leads Uncle’s men to their hideout in Hong Kong. They’re captured and brought back, but Vincent steps in, insisting he is the only one who knows the location of the hidden Picasso watches. Uncle sends Vincent and Yoh to retrieve them. The pair head to the post office to retrieve watch parts mailed back to Hong Kong but run into obstacles. After laying a trap door in the truck, Vincent and Yoh decide to confront Uncle and threaten to destroy the watches unless Chief and Mario are released. Uncle reluctantly agrees, and releases them. Yet as Yoh tosses the watches from the truck toward Uncle, a wave of Japanese hitmen arrives. Uncle orders his men to fire, but they’re swiftly eliminated. The hitmen seize the Moonwatch, while Uncle ends up only securing the Picasso watches. A gunfight drives the crew to flee through the trap door into underground pipes, where they seek refuge at Tung’s house and discover that a missing parcel had been mailed back to Japan.
In a mid‑credits moment, Vincent reveals that the three Picasso watches given to Uncle were actually frankenwatches, and he proudly displays the real watches to his crewmates. Meanwhile, Uncle—still unaware of the ruse—tries to sell the fake Frankenwatches to a Russian crime lord, who quickly identifies their hollow value. Uncle’s henchman abandons him, leaving a panicked figure facing Russian guns.
