A young boy named Toshio and his friends, while exploring an abandoned factory, are taken captive by gangsters. Toshi unwittingly discovers a signal device that will summon the cyborg superhero Electric Man Arrow. Arrow comes to the rescue, and, after vanquishing the gangsters' giant robot, entrusts Toshio with the signal device. However, the gangsters' mysterious leader X Fighter learns of this and uses Toshio in his plot to frame Arrow for a string of deadly sabotages. When Arrow finally confronts X Fighter for an explosive showdown, the shadowy link between the two superhumans is finally revealed. In the final chapter of this volume, Arrow faces an entirely different sort of problem, what to do with a gigantic dinosaur that scientists have discovered deep below the earth.