Set nearly three thousand years ago, the Amazons are a tribe of proud warrior women who have established a female-only state. The film opens with a tournament to crown a new queen. Antiope, a formidable competitor, defeats her rival Oreitheia in the final wrestling match and rises to the throne. Believing the tribe has grown lax, she imposes strict discipline, allowing sexual relations with men only once a year for procreation, and arguing for a more egalitarian society. This bold program is opposed by Oreitheia and other high-ranking Amazons, who plot to overthrow Antiope.
Because the tribe lacks men, the Amazons hire men from another nation annually for reproduction, a duty Antiope participates in. The Amazons then meet Greek soldiers led by King Theseus of Athens for the ceremony. Meanwhile, Oreitheia plots to sabotage Antiope by poisoning her water with an aphrodisiac, but the handmaiden drinks it instead, foiling the plot.
Intrigued by the Amazons, Theseus disguises himself as a low-ranking captain and has sex with Antiope, impregnating her. The encounter awakens a forbidden attraction in Antiope, who, to her surprise, enjoys the moment. The next day, during contests between the two groups, Antiope injures her leg while trying to outdo the Greek leader in show jumping, preventing intimacy that night. Theseus apologizes and tries to sway her views on men, but she remains steadfast in her beliefs. Secretly starting to develop feelings for him, Antiope fears showing weakness and orders an early departure.
Guided by a mistaken route through the Blue Mountains, the party falls into a Scythian ambush. Theseus recognizes his error and gathers soldiers to defend the Amazons. The Amazons, led by Oreitheia, retaliate by raiding Scythian villages, convinced that the Greeks themselves engineered the attack. Over the following months, Theseus grows fond of Antiope and camps near the Amazon city. He saves her from an assassination attempt and later slips into her chambers for another dangerous encounter, which she reluctantly accepts. Theseus also sends his wife, Phaedra to the city as a supposed feminist envoy from Crete to learn about Amazon society.
Suspicious, Antiope's followers trace the envoy back to Theseus's camp, revealing the deception. Seeing him with another woman, Antiope feels used and ends their relationship, planning revenge. With their cover blown, Theseus and Phaedra return to Athens.
Antiope gives birth to a son, a development that disappoints the Amazons who do not favor male offspring. The apparent loss of her child unsettles her, and as Oreitheia returns from the Scythian campaign, she regains some support within the tribe. Oreitheia tries to murder Antiope in her sleep, but Antiope anticipates the betrayal. The two wage a nude wrestling match during a thunderstorm, and exhausted, they eventually embrace and become lovers.
Antiope arranges another meeting with the Greeks, intending to mate and then kill them in revenge for the ambush. Despite grim prophecies from their priests, Oreitheia nudges her toward the plan. Antiope and Theseus reunite, and he confesses his love. After their intimacy, Theseus reveals that he knew about the assassination plot from treacherous Amazons and that he rescued their son Hippolytus. Antiope secretly leaves to see her child in Athens.
The other Amazons, except Oreitheia and a few loyalists, believe she was kidnapped and pursue the Greeks to prevent news of this dishonor from spreading. A battle ensues. To protect Antiope, Theseus has her tied to a carriage against her will. Both sides suffer casualties, and Antiope helplessly witnesses Oreitheia's death. Deciding there has been enough bloodshed, Theseus stops the fighting. In the aftermath, Antiope, recognizing Oreitheia's ambition, places Oreitheia's ring on her finger. Having been defeated, Antiope and the surviving Amazons join the Greeks on their journey to Athens.
Though saddened by the Amazon downfall, Antiope looks forward to her role as Theseus's political adviser and is relieved to learn Phaedra is his wife, not his lover.
