A young woman flees through the jungle while attempting to escape from Frank Lane, an American running an illegal child sex ring operation in Brazil.

Meanwhile, kickboxing champion David Sloan and his trainer Xian arrive in Rio de Janeiro for a championship bout.

After fighting off a pair of drunken assailants, he catches up to the boy who then brandishes a knife, but David easily disarms him and takes back the camera.

When the boy, Marcos, follows him back to the restaurant to reclaim the knife, Xian invites both him and his beautiful sister Isabella to join them for lunch, and they eventually become friends.

They purchase guns from an arms dealer and infiltrate a mansion owned by a pimp named Branco, eventually discovering that Lane is behind the child sex ring operation.

Lane and his henchman Pete force David through a series of grueling exercises designed to weaken him before his match with Martine, such as hiking with a backpack full of rocks and water-skiing without skis.

In the end, the police sergeant decides to cover up Lane's murder, and David arranges for Marcos and Isabella to attend school.