San Antonio, Texas. The bodies of various drug cartel members are turning up mangled and drained of blood. Tough DEA agent Carlos Seguin discovers that the grisly murders are being committed by a pack of chupacabras, which are lethal predatory creatures of local legend. Carlos, his feisty new partner Tracy Taylor, wayward estranged son Tommy, and several others make a desperate last stand against the bloodthirsty beasts at the famous fort The Alamo.—Woodyanders

DEA agent Carlos Seguin is called in to work on the second anniversary of his wife's death to view three drug runners that were mutilated. His new partner, Tracy Taylor, suggests the deaths are due to a pack of chupacabras, lethal predatory creatures of local legend. Shortly after that, one of his agent colleagues goes down while investigating a nearby area in the field. This is followed by the mauling of two college coeds heading to Mexico through the woods. Worse, nearly thirty party high school students, including his daughter, are attacked while celebrating Cinco de Mayo. Tracy shoots a GPS dart into one of the creatures, allowing them to be tracked. Carlos's boss tells him that this is not a DEA mission, but with his daughter involved, he persists. As the number of chupacabras increases, they infiltrate San Antonio. The GPS monitor says they are at a local industrial site. Carlos, Tracy, his estranged son Tommy and his gang eventually face down the entire pack. Their final stand occurs at the Alamo where a tour guide, Crockett, helps them strategize how to stay safe while fighting back.—Garon Smith