Hell lies under the Texas-Mexico Border. When the Acuña Cartel tunnels under the Rio Grande and into the United States, they tap into a vast cavern that’s home to a once thought mythical species. The massacre that ensues leaves 12 men dead, brings tunnel construction to a standstill. Losing money by the hour, the Cartel pulls Captain Jarrett Taylor out of retirement to lead a band of mercenaries under the Earth to eliminate an animal more savage than any human force they’ve ever faced. The mission quickly goes bad and plunges the team into a desperate battle of survival