The Gokai Galleon crew stumbles on a dimensional hole that has opened in the sky and a robot who falls from it. After it introduces himself as Bomper, the Go-ongers' support robot, the crew takes him to meet the former Go-on Red S?suke Esumi who reveals that the Gunman World is being terrorized by Disruption Officer Chirakashizky, a surviving member of the Gaiark Clan, and that Engines Speedor, Bus-on, and Bearrv have already tried to stop him, but were defeated instead. S?suke asks the Gokaigers to help out, but Captain Marvelous refuses to do so, claiming that they would not get anything from it, particularly after they have already received the Go-ongers' Great Power. S?suke decides to go by himself, but after his various failed attempts to reach the hole, Captain Marvelous and the others appear, and he says that he will give S?suke a ride if he wants. The group travels to the Gunman World, where they save several of its denizens from a group of Ugatz. They eventually catch up with Speedor, Bus-on, and Bearrv, and learn that Speedor and Bearrv have married, and that they have a son: Engine Machalcon. However, Machalcon is a reckless troublemaker who spends his time racing around in the Machine World rather than helping out his parents. Their reunion is cut short by Chirakashizky who challenges the Gokaigers to a duel. Captain Marvelous accepts the duel, and despite resorting to dirty tricks, Chirakashizky is defeated by the Gokaigers. During their battle with the enlarged Chirakashizky, the Gokaigers try to use the Great Power of the Go-ongers, but they are surprised when nothing happens. Despite the difference in power, they manage to take Chirakashizky with their own power. While the pirates confront S?suke about the reason why the Great Power is not working, they are contacted by Pollution President Babatcheed, the new leader of Gaiark, who reveals that he merely used Chirakashizky to lure the Gokaigers into the Gunman World, and by sealing the wall between dimensions, the pirates are now unable to return to the Human World, leaving the way open for the Gaiark Clan to conquer it.