Plot Synopsis

During a major drug deal in a tunnel just over the U.S./Mexico border, a pack of ravenous Chupacabras, legendary vampire-like creatures, attack, tearing the dealers apart. To DEA agent Carlos Seguin, descendant of Alamo hero Juan Seguin, it looks like drug violence. However, his new partner Tracy suspects that there's something else going on. Before long, Carlos realizes that they are using the drug smuggling tunnels to cross into the United States. Worse, in their hunt for food, the hungry creatures are making their way to San Antonio, the nearest urban center. When the Chupacabras attack the city, Carlos is forced to team up with his estranged son and his outlaw street gang in order to fend them off. With the beasts closing in from all sides, they end up taking refuge inside the fortified walls of the Alamo. Now, with hundreds of the blood-sucking creatures threatening to devour them, it will take a miracle and a lot of firepower to survive the siege.