A major convention of world-renowned scientists is coming to Steam City, but there is a problem- someone has been kidnapping the attendees. Narutaki narrows down the list of potential targets to the next two, and goes to warn them. Later, one of them is indeed snatched, but Narutaki and Goriki foil the attempt. Later, at the convention, it is revealed that the other, Dr. Gerhalt Von Halt, is the one behind the kidnappings. He wants the knowledge of the scientists to make his megamaton better than human. He claims his evil identity- Dr. Guilty- and tries to capture the remaining scientists. Narutaki is having none of it, however, and the battle is on. Dr. Guilty's megamaton is strong, however, and Goriki is badly damaged. Just when it seems as though the heroes will be defeated, the scientist Narutaki saved earlier gives Narutaki special bullets; with which the bad guys are at last defeated.