A beautiful young Spanish noblewoman dons a mask and battles injustice in 19th-century California. In the opener, Tessa (Tessie Santiago) investigates her father's death and is inspired to use her fencing skills to seek revenge. She battles a corrupt governor in 19th-century California.
Tessa learns village peasants are being shanghaied by Montoya to work in his mines, but is unaware they are part of a trap the colonel and Capt. Grisham have set for her.
Helm's medical skills are called into action when a fever ravages the town, but his antidote is stolen by Grisham, who plots to wrest power from Montoya by blackmailing the village unless the Queen of Swords can stop him.
Tessa searches for answers after the father of her childhood friend is mistakenly killed by an assassin whose real target was the shadowy Dr. Helm (Peter Wingfield), a very enigmatic man.
Tessa becomes a target after she fingers the killer of a peasant girl, prompting the wrath of the suspect's mother (Bo Derek), who plots murder to save her son from the gallows.
An ace Spanish swordsman hired by Montoya to dispose of the Queen is unexpectedly reunited with his long-lost love, Tessa.
Devastated by the murder of her godfather, Tessa is determined to bring the killers to justice, but she is in for a shock when a close friend is linked to the crime.
Tessa boldly plots to free two of Montoya's prisoners and learn the identity of her father's killer, but in doing so risks having her own identity exposed by a blackmailer.
The Queen's reputation is sullied by an impersonator (Elizabeth Gracen) who robs a shipment of gold, providing Montoya with a perfect excuse to rid himself of the avenger and reap a handsome profit in the bargain.
Helm (Peter Wingfield) is caught in a deadly showdown between the Queen and her latest nemesis, a bandit called the Serpent (David Carradine) who has slithered into town.
Grisham and Montoya learn of a pact between Tessa's father and two other Dons to divide the estate of a deceased comrade, and they plot to recover the fortune.
The King of Spain's power-hungry emissary (Ed Stoppard) arrives in Saint Helena on a mission to capture the Queen of Swords and oust Montoya from his governor's post.
The Queen has to rescue both Vera (Elsa Pataky) and her reputation when she is compromised by a former flame (Stephen Billington) who wants her husband's gold.
Tessa's uncle (Grant Russell) arrives from Spain thirsting to avenge the death of his brother, but Tessa risks his wrath to protect the man her uncle believes is responsible for her father's murder.
Tessa fears for Dr. Helm's safety when his former fiancée (Amber Batty) arrives in Saint Helena claiming to be on the run from an abusive husband (Simon MacCorkindale).
When Col. Montoya marches the garrison to Monterey, Tessa organizes the women of Saint Helena into a makeshift posse to save the town from Grisham's old nemesis, Krane (Anthony DeLongis).
Marta's long-lost love, Leonardo (Oliver Haden) visits Saint Helena in search of his paramour and becomes enmeshed in Montoya's scheme to trap the Queen.
The son (Alex Hassell) of a prominent couple becomes the target of Montoya's wrath when a dying man rides into town and accuses the son's family of deception and murder.
A pair of con men, Fenner and Roman (Darren Tighe, Ralf Moeller) convince Montoya they can hunt down the Queen for a fee, but have trouble keeping their word after she saves Roman's life.
The death of a Samurai master leaves his apprentice thirsting for revenge, an ideal scenario for Montoya, who insists the Queen of Swords is responsible for this crime.
Grisham (Anthony Lemke) corners the Queen in an abandoned mine, but a sudden earthquake leaves them trapped, forcing them into an uneasy alliance.
The Queen is accused of causing Vera's injuries after Grisham knocks the woman from her horse, prompting Montoya to establish martial law to stop the saber-wielding vigilante for good.