Lieutenant Rafael Santos is ambushed on his way to Monterey and left for dead when the ambushers take his identification and uniform. One of them, a killer named Anastacio, puts on the uniform and rides to Verdugo's, where Diego is discussing the investment deal. The real soldier is not dead, however, and his beautiful white horse stands guard by his side.
Anastacio tries to drug Sergeant Garcia, hoping to steal his money belt, but the plan fails and the money is delivered to Diego. The Verdugos will take the money to San Francisco to invest it, with the fake Santos and Romero acting as guards. Diego and Bernardo then head back to Los Angeles. On the way, they discover the real Santos lying in the road. He tells them his name and faints, but they have learned enough to know the Verdugos are in trouble.
Diego takes the soldier's horse and sets off after the merchant and his daughter, who have been attacked by the fake Santos. The bandit and Zorro engage in a sword fight and the masked man wins. He orders Anastacio to name the other thieves. Just then, Romero kills Anastacio, claiming he was too upset to think clearly. Zorro warns the travelers to be careful on their way home to Monterey, then rides off into the night.
Zorro a protégé Anna Maria Verdugo et son père, attaqués par des bandits. La jeune femme, qui voudrait remercier son bienfaiteur, demande à Zorro ce qu'elle pourrait faire pour lui mais ne reçoit pas de réponse...
Pablo és társai megtámadják a Monterey-be tartó Santos hadnagyot és elveszik a papírjait. Anastacio Santos ruhájában és papírjaival jelentkezik Verdugónál azzal, hogy őt küldték a pénzt kísérni San Franciscóba. Diego az indulás előtt átadja a pénzt Verdugónak, aki a lánya, az ál-Santos hadnagy és Romero társaságában útnak indul a kikötő felé. Diego és Bernardo is útra kell hazafelé, és útközben Fantom, a hadnagy lova segítségével rátalálnak a haldokló tisztre. Zorro Fantom hátán indul Anna Maria és az apja megmentésére, sarokba szorítja az ál hadnagyot, de mielőtt fontos részleteket tudna meg tőle, az megpróbál megszökni, ám Serrano lelövi. Zorro furcsállja, hogy Serrano oly sebtiben megölte az útonállót.
Il Luogotenente Rafael Santos viene aggredito da un gruppo di malviventi durante il suo cammino verso Monterey. I banditi gli rubano l’uniforme e poi lo feriscono a morte. Anastacio, uno di loro, indossa la divisa e cavalca all’hacienda dei Verdugo dove Diego sta discutendo sulle modalità della consegna del denaro. Diego fa avere i soldi a Verdugo il quale parte per San Francisco con la figlia, Romero e Anastacio come scorta, mentre Diego e Bernardo ripartono per Los Angeles. Durante il viaggio i Verdugo scoprono che Anastacio è un impostore e vengono attaccati. Intanto Diego viene attratto da un bellissimo cavallo bianco che cavalca senza il padrone e seguendolo scopre il corpo del Luogotenente Santos che, in fin di vita, gli dice di essere stato assalito dai banditi. Zorro interviene giusto in tempo per salvare i Verdugo mentre Romero uccide Anastacio per non permettergli di fuggire. Zorro consiglia ai viaggiatori di tornare a Monterey e poi sparisce cavalcando nella notte.
