In a matter of moments, Alejandro Reis, known as Alex, experiences a life-altering revelation: he is not an American citizen. His parents had brought him across the Mexican border as an infant. Meanwhile, Flora Hendricks, a native of Missouri, decides to flee her home. Alex is deported to Mexico, and in a twist of fate, Flora, caught shoplifting, ends up on the same deportation bus as Alex. Once they arrive in Mexico, both quickly realize they are in over their heads. They soon discover that Tijuana and many other border towns are plagued by extreme violence and dominated by dangerous, feuding criminal groups.