When Hong Kong police inspector Lee Chung-chi (Louis Koo) is informed about the sudden disappearance of his 16-year-old daughter Lee Wing-chi (Hanna Chan) during her trip to Pattaya, he decides to travel to Thailand to search for her daughter's whereabouts. There Lee receives assistance from local Chinese detective Chui Kit (Wu Yue (actor)) and his Thai colleague Tak (Tony Jaa) and also encounters American gangster Sacha (Chris Collins).