Sergeant Garcia receives a mysterious note from Zorro. The happy soldier reads that Zorro will give himself up. When he returns for his sword, it is gone, so he sadly returns to the cuartel without having captured his foe.

The King's tax collector and his nephew are stopped by conspirators, while on their way to Los Angeles. The conspirators threaten the men unless they cooperate, then they seize Morales' official documents.

A quiet day in the pueblo is abruptly changed when a stranger is killed by an arrow, apparently the victim of an Indian attack. Diego helps Sergeant Garcia inspect the body for clues and finds another mysterious eagle feather, this time on the fake Indian arrow. Other than that, there is no hint as to who the stranger was or why he was killed.

A peaceful protest by a group of peons upset with taxes turns violent when one of the Eagle's men throws a rock through the magistrado's window. Galindo uses this as an excuse to order severe measures against the peasants, a move that upsets Don Alejandro. The other landowners want to set up vigilante posses to punish the peons, but Alejandro argues on the side of reason.

Ramon Santil has just inherited his father's ranch and holdings, and some bad news. The magistrado tells him there's a high tax that must be paid at once or he will lose the land, and Ramon doesn't have the money to pay it. In desperation, he sells all of his cattle to Carlos Urista, a recent arrival in town whom Diego suspects as another of the Eagle's men.

Don Alejandro tells Diego he's received a letter from a friend in the capital telling him that the new commandante, Capitan Juan Ortega, has the reputation of being an honest and fair man. When Ortega arrives, he doesn't act that way. He treats Sergeant Garcia with contempt and is openly arrogant toward the civilians. The reason for this is revealed when Ortega meets the magistrado and informs him that the real commandante has been ambushed and murdered, on orders of the Eagle.

The plans of the fake commandante and the magistrado go awry when Ortega spots Diego talking to Rosarita Cortez, a childhood friend who has recently returned from the capital. Ortega fears she will recognize him from her journey, for it was during that trip that he murdered the real Ortega and assumed his identity. Bernardo overhears the two villains planning her death, and notifies Diego.

The magistrado's plans to aid the Eagle may suffer a setback when a new commandante arrives in the pueblo. Unlike the fake Ortega, Capitan Toledano is loyal to the King and beyond corruption, yet he must be eliminated if the Eagle's plot is to succeed. Toledano's jealousy over his pretty wife Raquel is the key to the magistrado's newest scheme.

Magistrado Galindo has smuggled a supply of weapons into the pueblo, intending to use them when the Eagle orders the overthrow of the government, but he has been unable to get a supply of gunpowder. The army has a large stockpile at the cuartel, and the magistrado decides to steal it for his use

Capitan Toledano plans to interrogate two prisoners who were seized when the gunpowder was recovered. The prisoners warn Figueroa, one of the magistrado's men, that they will talk unless someone helps them escape. Instead, they are found dead in their cell the next morning. A doctor examines the bodies and suspects murder, but the magistrado announces that it was suicide.