After cleverly extricating himself from the torture chamber and rescuing Ramon (William Corson) and his sister Volita (Sheila Darcy), Zorro (Reed Hadley) changes back into his foppish alter ego, Don Diego. Confessing his newfound suspicions of Manuel (John Merton), Diego hatches a plan with Ramon that may prove once and for all whether the commandant is the nefarious megalomaniac Don del Oro. Tricking Manuel into helping him retrieve a letter that supposedly will unmask the master criminal, Diego is ambushed by Moreno (James Pierce) and his men. Manuel betrays that he knows full well what Moreno is after -- the nonexistent letter -- and is forced to explain himself to the council. In order not to betray the real Don del Oro, the commandant makes a quick getaway by hijacking the stage. Zorro, in hot pursuit, attempts to stop the speeding coach but is apparently shot by the desperate Manuel.
by Hans J. Wollstein synopsis