The US–Mexico borderlands have lived in the popular imagination as the locus of danger and horror, as the “other side” poses violent and unimaginable threats to those who dare cross the border. Situated in the outskirts of both the American and Mexican nations, the binational borderland region embodies ambivalence, otherness and a loss of civilization or humanity. Borderland monsters often play with a wilful monstrosity, as they express the ambiguity, resistance and resilience necessary to cope with their inherent in-betweenness, marked by their gender, ethnicity, legal status and/or cultural assimilation. Crossing the Boundary: The US–Mexico Borderlands in Contemporary Horror tackles the most recent evolution of borderland representation in horror texts, focusing on popular culture and including films, comic books and TV series, to provide an insightful review of themes and tropes specific to the binational region and its highly politicised discourses.