Two Vietnam War veterans are sedated and thrown into the sea on the orders of a crime boss. Two sailors put on the veterans' clothes and Colonel Morris confuses them and thinks they are the veterans.

The Dragon is in prison ready to escape and take revenge on those who stopped. This will help a mafia organization that moves in the world of illegal betting related to martial arts fights worldwide and also linked to drug trafficking. In prison, the Dragon is a sinister character, McClain (Randholp McClain), an American imprisoned for killing their opponents. But once released sent to compete in the World Martial Arts Championship with Hector Echavarria, Argentine and world champion wrestler.

The Colonel of the Extermineitors has discovered that McClain (McClain Randolph), old enemy of the organization, crime has left to live quietly in Iguazu Falls and wants working for him. That's how you develop a plan for Guillermo (Francella) perform McClain recruiting mission. The Colonel knows that William has a twin brother who never met and convinces him that the former offender is his lost brother ... Installed in Niagara, evading the thief who wants to kill Nico, an orphan who is in charge of William, MacClain convince that he is his twin brother, getting together to Buenos Aires to join the group of the Extermineitors.

This time the unusual "Extermineitors" must confront a secret organization that aims to make a fighter bionic implants (Randolph McCIain), test its performance, and create a multitude of "indestructible" men to dominate the world. Guillermo (Guillermo Francella) and world karate champion Hector (Echevarría) form part of a secret martial arts tournament to expose this evil group. To these is added Nico (Javier Belgeri), an orphan child (Son of Emilio Disi character played in previous installments) fan of this type of gear, which provides assistance in this crucial fight