Kham (Tony Jaa) has resumed a quiet village life with his "brother"/elephant, Khon, back in Thailand. Job, an oddball who loves playing with electrical devices, has lived in the village for some time and has earned the trust of the locals. Unknown to Kham, he's an agent of an arms dealer known as Mr. LC (RZA). A fan of Kham's exploits, LC had Job keep tabs on Kham without his knowledge. Things change for Kham when a merchant, Suchart Vilawandei (Adinan Buntanaporn), wants to buy Khon, but Kham refuses to sell Khon. Suchart gives his business card to Kham in case he changes his mind.While eating with the local villagers, Kham feels something is wrong and returns home to find that Job has been beaten and Khon has been taken by Suchart. Using the business card that Suchart gave him, Kham goes to Suchart's home to get answers but only finds that Suchart has been killed moments earlier. Suchart's two nieces, martial artists Ping-ping (Yanin "Jeeja" Vismitananda) and Sue-sue (Theerada Kittiseriprasert) arrive and believe that Kham must be responsible. The two attack him, but he evades and escapes; the authorities are alerted and the police give chase.While running from the law, Kham encounters Mark, who fakes being assaulted and allows Kham to escape. Later on, they secretly meet to learn more about the situation. Mark himself is in Thailand on a job for Interpol investigating a recent terrorist plot involving the peace talks between East Katana and West Katana in Bangkok.Kham is attached by Suchart's nieces as well as a biker gang. Kham fights through them and faces a small group of LC's fighters. LC himself is a great admirer of martial arts and has gathered his own personal group of fighters ranked according to their strength. LC has his second-strongest fighter, No. 2, take on Kham, while the girls are also interfering. No. 2 kills Sue-sue, leaving Ping-ping to grieve. Kham loses the fight to No. 2 due to a needle stuck to his neck from the fight with Ping-ping. No. 2 realizes that he only won the fight because Kham was handicapped, and takes him to LC.At LC's base, Kham finds his elephant and also discovers that Job is a traitor. Kham's enemies tie a specially made remote-controlled electrical device to shock Kham as well as Khon at the same time every time Kham disobeys. LC wants Kham to join him and uses the device to force Kham to help him assassinate a political figure related to the peace talks. LC also brands Kham on his chest as his fighter No. 1.Mark is suspected of foul play by other Interpol agents. After he fails to capture Kham, he is told to go home. However, Mark finds Kham and helps him remove the electrical device. Mark also encounters Ping-ping and takes her to examine her uncle's body at the coroner's office, where it is explained to her that Suchart was killed by three powerful combo punches, the same method of killing that happened to Sue-sue. Ping-ping realizes that Kham was not the killer but rather No. 2.LC, Job, No. 2, and Kham all go to a country temple to help war profiteers assassinate both leaders at the Katana peace talks to incite war and sell more weapons. Kham infiltrates the temple and fights against all of LC's men and No. 2. Kham and Ping-ping team up to fight against their mutual enemies. Ping-ping ignites an entire floor filled with gasoline in an attempt to burn No. 2, but No. 2 avoids the explosions and fire and finds Kham.Kham, fighting one level below Ping-ping, takes advantage of the fire, setting his own shoes on fire to using them to defeat his enemies. They in turn copy him. Kham then fights No. 2 again, this time further below, on the train tracks. The two fight over a live rail and take advantage of the electricity to shock each other while fighting. Kham knocks out No. 2 and confronts LC. To Kham's surprise, LC is highly trained and has marked himself as No. 0. The fight is short because both men fall and LC is knocked out.Kham recovers and finds Khon. He tells Mark that there's a bomb threat, and Mark tries to explain this to his superiors but they won't listen to him. Mark decides to scream out that there's a bomb and it scares everyone away. Kham finds Job, and the two discover that Khon's tusks have been cut down and replaced with prosthetic tusks that are rigged to explode. Kham tries to find a way to save Khon, but LC and No. 2 interfere.No. 2 and LC take on Kham in a two-on-one fight while Kham is busy holding Khon's tusks to prevent them from falling out and exploding. With the help of both Ping-ping and Mark, No. 2 is defeated and LC is killed after Kham releases the tusks and kicks them away at LC. The explosion kills LC and knocks both Kham and Khon over the cliff and into the ocean, but they survive.