Lola de La Pena yearns to be free from the societal expectations of a young Mexican lady of her station. She spends her days pretending to be delicate and proper while watching her mama cure the sick and injured with sal negra (black salt), a recently discovered magic that heals even the most mortal of sicknesses and wounds. But by night, she is Salvacion, the lady vigilante protecting the town of Coloma among the rising tension in Alta California after the signing of the Treaty of Guadalupe Hidalgo.

But one night, a woman races into town, barely alive, with a horrifying tale of how her town was obliterated by the potent and deady sal roja, a magic capable of obliterating anything it touches and the man who wields it: Damien Hernandez. When Hernandez arrives the next day with a party of fifty strong and promises of returning Alta California to Mexico, Lola knows he plans to bring the region under his rule - all he needs is the next full moon and the stolen, ancient amulet he carries to mine enough sal roja to conquer the land. Determined to protect everything she loves, Lola races against time as Salvacion to stop him. But she didn’t count on the distracting and infuriating Alejandro, who travels with Hernandez but doesn't seem to share his ambitions. With Hernandez getting closer to his goals, Lola will do anything to foil his plans, even teaming up with Alejandro - who she can’t help but fall in love with.