The governor of California is attacked during a visit to Los Angeles with his daughter and aide, and barely escapes with his life. Taken to the de la Vega house to recover, he is much too weak to travel for several days. The aide, Capitan Arrellanos, tells Diego he suspects the attack to be the work of the Rebatos, a group that wants to sever ties with the government in Spain. Arrellanos declares himself acting governor until the wounded man recovers and orders an armed guard placed around the house. Several days later a mysterious stranger tells the capitan that if the governor were to die, he would become the true ruler of all California. Arrellanos succumbs to the temptation and orders the guards removed. This makes Diego and Bernardo suspicious, so while Diego dresses as Zorro, Bernardo uses a secret passageway to keep watch over the ailing governor. This precaution proves wise when a stranger sneaks into the room and tries to kill the governor. Bernardo steps out and knocks the attacker unconscious. Zorro takes the governor to another room and puts the would-be killer in the sick man's bed in his place. Two more men try to kill the governor and Zorro fights them both, but one succeeds in plunging a knife into the covered figure on the bed. Not until the next day do the killers learn they have failed to assassinate the governor, and instead killed one of their own.
Elenco: Guy Williams , Gene Sheldon , Henry Calvin , Jolene Brand , Eugenia Paul , George J. Lewis , Guy Williams , Henry Calvin , Jolene Brand , King , Richard Anderson .