While vacationing in Mexico, a young couple and their son learn about the legend of La Llorona, the evil spirit of a distraught mother who lurks near the water's edge, striking fear in the hearts of all who see her. La Llorona torments the family mercilessly, snatching the boy and trapping him in a netherworld between the living and the dead. With help from a local taxi driver, the couple race against time to save their only child from an unspeakable evil that grows in strength and power.