Hong Kong cop Lee (Louis Koo) goes on a search in Thailand for his missing daughter Chi (Hanna Chan). Thai police officers Chui Kit (Wu Yue) and Tak (Tony Jaa) let Lee join the investigation, and they begin tracking down the culprit. As they get closer to the truth, they realize that the case is more complicated than they expected, and the mastermind behind it is not someone they can deal with…