The Old Summer Palace fell prey to a devastating looting and fire by a coalition of Anglo-French forces during the Second Opium War. Among the treasures that vanished were the twelve bronze heads representing the animals of the Chinese zodiac.
In present times, these once-stolen artifacts are auctioned off by MP Corporation. Enter JC, tasked with the mission of locating the missing bronze heads, with the enticing promise of a 10× bonus upon successful recovery. Operating under the alias of Martin, a reporter from National Geographic, he initially consults Professor Guan (Sang-woo Kwon), who previously fashioned identical replicas of the heads for scholarly study purposes using his research team.
Equipped with specialized gloves, JC scans the bronze heads to enable his clandestine organization to produce highly realistic replicas. His journey takes him to Paris, where he seeks out a woman named Coco (Qi Shu), recommended by Guan, for leads on the location of two missing heads. During an audacious infiltration of a mansion, JC manages to unlock a secret vault and discovers the sought-after bronze heads, along with a valuable painting known as "The Roses" and numerous other national treasures thought to be lost forever. Despite being caught red-handed, he narrowly escapes with the artifacts, though Coco witnesses the entire escapade and is left in shock.
Amid the chaos, JC arranges to meet Coco at a nearby boathouse while evading the mansion's security. There, he confides in her about his affiliation with a secret organization dedicated to reclaiming lost relics for China. Just as the mansion's guards converge upon them, the police are called, and the trio—JC, Coco, and Simon—is ultimately cleared of any wrongdoing and released.
Their adventure continues as they receive an invitation to a castle owned by Catherine (Laura Weissbecker), unaware that suspicious guards from the mansion are tracking them. Tension rises when they discover that Catherine's great-great-grandfather was the captain of the ship, Indestructible, involved in the looting of the Old Summer Palace. An emotional confrontation ensues between Coco and Catherine over this revelation. Inside the castle, they unearth numerous treasures, including the bronze head of the Rooster, and devise plans to transport their finds.
As a gesture of goodwill, JC assures Catherine that he will help locate her ancestor's remains. Their quest leads them to a seemingly deserted island rumored to house the treasures of the Indestructible. JC instructs Coco and Catherine to remain behind, yet they disregard his command and venture out on their own. As they become ensnared in thick vines, JC rushes to their aid. During their exploration, they inadvertently stumble upon the remains of the Indestructible, along with additional bronze heads and a vast hoard of gold. However, this discovery attracts the attention of the mansion's guards, and in a surprising turn of events, local pirates descend upon the scene and capture everyone.
After an intense skirmish, JC and his crew manage to escape the island using a cleverly rigged log, leaving the guards behind in the hands of the pirates. Back on their yacht, Coco accidentally uncovers the genuine purpose behind JC's mission and confronts him about it. In the midst of all this, the log carrying approximately eight tonnes of gold tragically sinks. However, their efforts do yield results, as JC and his team are rewarded for the recovery of some of the bronze heads. Their elation is short-lived as they learn that the supposedly-missing Dragon head has been in the possession of MP Corp all along, thwarting their hope for a hefty bonus.
The growing protests led by Coco and her fellow students regarding the sale of national treasures attract international attention. Things take a dark turn when three of her students, including her younger brother, go missing. In desperation, Coco seeks JC's help once more. Upon contacting MP Corp, he is granted access to their secret facilities, where almost exact replicas of the artifacts are manufactured to be sold as the genuine article at auctions. In a fateful encounter, he faces off against Vulture, a long-time rival and unscrupulous treasure hunter, though their battle ends unresolved.
In a tense negotiation, JC attempts to convince MP Corp to sell "The Roses" at a discounted rate to secure the safe release of the three hostages. When MP Corp declines, JC makes his way to the heart of the facility, where a botched maneuver by a guard activates a furnace explosion, obliterating much of the premises. Ultimately, JC agrees to exchange the precious painting for the release of the captives, while foregoing any claims for damages incurred.
The tension escalates further when the Dragon bronze head, anticipated to attract record bids, faces a lack of interest due to mounting pressure from activist groups. In a drastic move, MP Corp threatens to dispose of the relic in an active volcano during their operation titled "Let the Dragon Fly" if bids aren't submitted by noon. As the deadline approaches with no bids placed, Vulture leads a group of sky divers to fulfill the threat. JC bravely intervenes to prevent the relic from being lost forever, suffering significant injuries in the ensuing airborne conflict. Out of respect, Vulture relinquishes the relic to the incapacitated JC.
In the aftermath, the owners of MP Corp are arrested for their possession of "The Roses." The film concludes with JC recuperating in a hospital, on good terms with all involved—including Vulture—and joyfully reconnecting with his wife, who pays him a visit.
