Olga, owner of a boarding house, loves his brother, Billy, very much. When Billy is having lunch with Cindy, he meets Lea, the daughter of an archaeologist. Lea's father found a precious stone, which makes Mongol want to seize the stone. Mongol kills Lea’s father, but does not find the stone. Apparently, Lea's father had sent precious stones map to Leah. Mongol tells Dora, Ayu, and Emon to find Lea. Lea hides the map in Billy’s pocket secretly. After escaping Mongol, Lea is looking for Billy to get the map. Lea manages to get into Billy’s room but the map is not there. Lea, spotted by Billy, tells him what she wants. Billy does not believe her. Suddenly Mongol’s men come and seize Billy and Leah. Because Lea does not want Billy hurt, she says that the map is somewhere. Lea goes with Mongol’s men. This search makes Billy and Leah become close. Billy immediately returns home knowing that Olga is ill. Billy gets Olga’s heritage.