A young woman of humble means reinvents herself to avenge those who cruelly mistreated her. Corazón Indomable tells the story of Maricruz Olivares, a beautiful young woman who grew up poor in the Mexican countryside. When she and debonair pilot Octavio Narváez meet by chance, they fall in love. However, Octavio's snobbish family despises Maricruz for her humble origins and subjects her to countless humiliations, forcing her to flee to Mexico City. There, her life changes drastically when a kind, paternal millionaire takes her under his wing and transforms her into a refined, successful business woman. Reborn with a new identity, and armed with wealth and power, Maricruz returns to the ranch determined to seek revenge at any cost.