In a fictional land named Florin, a young woman named Buttercup and a farmhand named Westley fall deeply in love. However, they are separated when Westley departs to seek his fortune so they can marry. Years pass with no word from him, and Buttercup hears that he has been killed by the infamous Dread Pirate Roberts. Resigned to her fate, Buttercup becomes engaged to Prince Humperdinck, the heir to the throne of Florin, despite having no love for him. Just before their marriage, Buttercup is kidnapped by a trio of outlaws: the intelligent Vizzini, the powerful giant Fezzik, and the Spanish swordsman Inigo Montoya, who seeks revenge for his father's murder.

The outlaws' plan to start a war between Florin and the neighboring country of Guilder by killing Buttercup is unexpectedly challenged by a masked man in black who follows them. One by one, he overcomes the group using his wits, swordsmanship, and physical prowess. Meanwhile, Prince Humperdinck and his sadistic henchman, Count Rugen, pursue the kidnappers in an attempt to rescue Buttercup. As the story unfolds, the true identities of the masked man and the motivations behind his pursuit of Buttercup begin to emerge, revealing a deeper connection to her past and intertwining the fates of all the characters involved.