Lek Yai Mai Kaewko Aew Duay Kon

The story begins with Bandit, a high-end antique collector and father to two young boys, Lek (Small) and Yai (Big). Bandit possesses a priceless artifact that catches the eye of Hock, a ruthless Thai-German mafia boss. During a violent heist at their home, Hock’s men murder Bandit. The boys’ mother, Khun Ying Phiangphen, manages to escape with Yai, but the family is torn apart. The brothers are separated for 21 years. Yai grows up under the protection of his grandfather, Kampanat Phaireephai, a legendary former Police Commissioner, and becomes a dedicated officer himself. He is haunted by the memory of the killer wearing a Nazi-style skull ring.
Meanwhile, Lek was supposed to be executed, but a soft-hearted henchman named Somphop spared him, leaving him to be raised by Detsak in the slums. Lek grows up to become "Moses," a "saintly thief" who steals from the corrupt to help the poor, using a prestigious art gallery as a front. When Somphop is later murdered by Hock’s men for a Picasso painting, Lek spots the same skull ring on the killer. Before dying, Somphop reveals the truth about Lek’s origins.
The brothers’ paths finally cross during a global antique exhibition and auction. While Yai is there to provide security, Lek is there to steal from the corrupt officials in attendance. When Hock’s gang raids the event, Lek saves Phiangphen, meeting his biological mother for the first time without realizing it. Eventually, Lek and Yai decide to form an uneasy alliance to take down Hock. They are joined by Nisa, an Interpol agent specializing in antiquities, and Seksan, a government official who remains suspicious of Lek’s criminal background.
As the mission intensifies, Lek infiltrates Hock’s hideout to steal a vital antique pocket watch, but he is wounded and treated by Dr. Lena, a Thai-German doctor. Lek falls for her, only to discover a heartbreaking truth: Lena is Hock's daughter. The situation becomes a chaotic three-way war when Likhit, a corrupt businessman, emerges as a "third hand" trying to steal the watch for himself.
The climax takes place at a warehouse where Hock holds Lek’s foster family hostage in exchange for the watch. During the final confrontation, the truth is fully revealed: Lek and Yai are brothers. In a desperate battle, Yai is severely wounded while saving Lek, and the brothers finally take down Hock—the man who murdered their father.
In the end, as Yai recovers in the hospital surrounded by his family and Nisa, his grandfather mentions a new big case. When Yai tries to claim he can handle it alone, Lek smirks and insists on joining, repeating the show's motto: "Size doesn't matter... let me in too!"