When a massive amount of gamma radiation is detected beneath the desert of Iran, the world is on edge. Is it a nuclear weapon - or worse? Alex Hunter and his highly trained incursion team are sent to find out. When they arrive at the ruins of Persepolis, they find an underground facility but no weapons, no scientists - not even radiation. With war brewing in the Middle East, another gamma spike is detected... and someone, or something, is draining the fluids from the bodies of Iranian soldiers in the desert. Now it's up to Alex to follow the traces of radiation to the ancient caves of Arak, where he'll come face to face with a creature from his darkest nightmares.