Jeff forces a fight just before Rocket Man's identity can be disclosed through the print, which Jeff destroys as Dirken escapes. He remembers an ornate ring worn by an undisclosed confederate the night the photo developer was stolen. At a conference meeting next day, Jeff seeing the identical ring on Prof. Conway's finger, accuses him of complicity. Alarmed, Conway flees to phone Dr. Vulcan, whom be believes to be an innocent member of the project. Vulcan pretends to help and sends Conway to Dirken, who forces the professor to write a confession implicating himself as Dr. Vulcan. Jeff, as Rocket Man, flies to Dirken and Conway. Conway identifies his ring as a fraternal club ring worn by many Science Associates. Dirken kills him and escapes out the window, swinging across a suspended phone wire to an adjoining roof. As Jeff pursues, Dirken severs the wire, sending Jeff plunging to his death.
