Five years after a failed rescue in Inner Mongolia, the former mercenaries drift apart, each following a different path under the guidance of their adoptive father and mentor, Cao Sir Eric Tsang Chi-Wai. The team—headed by the resourceful Lion Ekin Cheng Yee-Kin and including the hot-tempered Crater Jordan Chan Siu-Chun, the greedy Bill Michael Tse Tin-Wah, the cool-headed Calm Chin Ka-Lok, and the simple, content Mouse Jerry Lamb Hiu-Fung—has gone their separate ways, each nursing memories of what they left behind.
Five years later, Lion travels to Africa, where he uses his skills to deliver medicine from a pharmaceutical company to a refugee camp in need. The camp is strained by a new epidemic, and Zoe Chow Charmaine Sheh Sze-Man, a doctor and Lion’s girlfriend, urges that the new medicine be shared quickly. Meanwhile, Bill reveals that a shipment of the same medicine is due to move to Budapest Airport in Hungary under the protection of Joe Phil Chang, the deputy head of a Special Operations unit. Fueled by a belief that they can help people again, Lion gathers his brothers for one last, dangerous job aimed at taking down the Intelligence Bureau that guards the operation. They rally the group—joined by their mentor and father figure, Cao Sir Eric Tsang Chi-Wai—and Cao Sir’s daughter Lulu Zhang Yamei—to set a trap in the city, planning to swap a monitored truck with a decoy.
The plan initially seems to work. The brothers lure the guarded truck into a tunnel, swap it, and push ahead with their scheme. But Crater, driving the decoy to a train depot, notices something is off. Mouse unlocks the truck and reveals a stark truth: the vehicle is loaded with gold, not medicine. Bill had secretly conspired with Rice Sergej Onopko to siphon off the money earned by the Intelligence Bureau from selling arms, using the brothers as cover. When Rice and his henchmen arrive at the depot, they find Cao Sir and Lulu still present and fear they might expose the scheme, so Bill is ordered to shoot them to silence them. A fierce gunfight and a high-stakes car chase erupt. Cao Sir is wounded—shot in the leg and left immobile—while Rice refuses to pay out any reward. Bill shoots Rice, seizes the gold, and claims his prize, with Rice’s subordinates falling in line behind him.
Lion, determined to protect his family and expose the betrayal, drives his car straight into the police station to shake off pursuers, and he is arrested in the aftermath. As he waits, he begins to piece together the fragments of what happened and the choices he and his brothers made.
The story then unfolds in a sprawling flashback that explains why these five strangers became a family. Orphans since childhood, they had once fought to curb trouble at an entertainment venue, got arrested, and were rescued by Cao Sir, who trained them to become mercenaries. They grow into a unit they proudly call family, calling Cao Sir “Dad” and viewing him as a steadfast mentor. After Lion serves a sentence, Crater waits in the slums, Calm tends bar, Mouse runs a hot spring inn with Inspector Cao and his daughter in Kumamoto, Japan, and Bill purchases an island in the distant Black Mountain. A year later, Lion reunites with Crater and Calm in Japan to visit Cao Sir and Lulu, while Morimoto [Yasuaki Kurata] joins their gathering, and the atmosphere shifts as a festival mood—Morimoto announces a sake festival and invites them to participate.
In the next phase, the group discusses the debts and loyalties that have followed them. They plan to lure Bill back to a car show in Fukuoka for questioning, while Bill’s henchmen close in. The pursuit spills onto the island where Bill has entangled himself in power and danger, and Cao Sir’s presence is felt as the brothers vow to bring him to justice. They confront Bill at his island base, and a brutal, protracted gun battle erupts in a church-like compound where Bill’s defenses are knocked down piece by piece. In a final twist, Bill manipulates Crater into turning the weapon against himself, and Joe retrieves the gold—though he will not admit whether its loot was obtained illegally.
Back in the present, Lion returns to the refugee camp to meet Zoe and discovers that Bill had, in fact, sent medicine to the camp during his imprisonment, underscoring the personal cost of the conflict and the blurred lines between mercy and malice.
This saga blends action and loyalty with a deep exploration of how a band of orphans—bound by blood, debt, and mutual care—navigates betrayal, justice, and the bittersweet truth about what it means to be family.
