A magical sword in a rock lands in San Lorenzo, promising whoever can draw it city hero status. Puss lets all eager townsfolk try, confident he alone qualifies, but to general surprise the talking Goodsword chooses reluctant Dulcinea and calls shocked Puss her sidekick. He still trains and motivates her to ward off fiends. The real challenge however arrives in the person of knight Thriffith, who wields an evil blade. Puss must solve the riddle why Goodsword refuses to defeat him.