This is a story of passion and revenge between two rival families, the Valdeses and the Ramirezes, who live in a town called San Andres.
The most obvious point of contention in this feud is The Spring, a rich fountainhead of crystal clear water that, as fate would have it, irrigates the land of the Valdes family and not the neighboring property, a rich hacienda known as "Piedras Grandes," where the best fighting bulls in the country are bred, and which belongs to Justo Ramirez.
However, the real reason for their mutual hatred is a shocking secret that takes place behind closed doors. Justo is married to Margarita Insunza but is having an affair with Francisca Rivero, the wife of his neighbor and rival, Rigoberto Valdes. This adulterous liaison, based on deceit and lust, is the root of a burning resentment that will slowly bring down the two families.
Rigoberto and Francisca Valdes have a beautiful daughter named Alfonsina-the heroine of this story-who was born around the same time as Alejandro, the only son and sole heir of the Ramirez family. The demanding life on their ranches keeps the two of them apart for most of their childhood. However, in spite of having been brought up in an atmosphere of prejudice and hatred against each others family, when they finally meet again as young adults, they are struck by a mutual attraction that neither dares admit.
The first encounter between Alfonsina and Alejandro is far from cordial. Accustomed as they are to hating each others name, they confirm something they had always known, namely that a Valdes and a Ramirez will always be enemies. The resentment of Alfonsinas family grows even deeper when Justo Ramirez, through trickery, achieves his hearts desire: to become the owner of The Spring. The loss of their property forces Alfonsinas family to leave San Andres and Alfonsina, filled with rage, vows that she will do everything in her power to recover the land that has been in her family for so long. Without giving any explanation, she leaves town, knowing that she is also leaving behind the possibility of finding love with Alejandro.
Thus, believing they are finally rid of their sworn enemies, Justo and Margarita Ramirez agree that the best candidate to become Alejandros wife is their niece Barbara Luna, an attractive but somewhat calculating and frivolous young woman. Barbaras family, aware of the advantages that this marriage will bring them, is thrilled with the idea and they quickly formalize the engagement. This event coincides with Alfonsinas return to San Andres. Naturally, Barbara sees this new arrival as a threat and does everything in her power to keep Alfonsina away from her future husband. Nevertheless, the power of love is stronger than all of Barbaras malicious intrigues, and Alfonsina and Alejandro finally confess their love for each other and renew the relationship that had ended so abruptly.
But the ill will that has poisoned the two families condemns the young lovers to suffer rejection and cruelty, and in order to survive, their love must break down the barriers that fate has placed in their way, so that The Spring will once more become the source of hope and happiness.