We begin in the mountains to the north of Spain 32,000 years ago where a mortally wounded young Neanderthal male seeks refuge in cave after being savagely attacked by a Cro-Magnon hunting party.

The main story, however, is contemporary. When Oxford-trained American archeologist MICHAEL CORBETT is hired by the University of Salamanca to lead an expedition to explore a newly discovered cave in the Pyrenees, he is contacted by the CIA. For along with his impeccable credentials, Corbett is actually an exfiltrator” — a freelance operative who specializes in the location and extraction of high value targets under extreme danger and duress.

Several weeks earlier in the holy city of Najaf, a key Iraqi cleric was a victim of an ISIS terror attack. Should he die the prospect of peace and stability in the region dies with him. The only chance is to locate his son, Tariq, who has gone missing somewhere in the Basque mountains to the north and reunite him with his father. At Oxford, Corbett and Tariq had been close until a woman came between them. That woman, a doctor named Amaia Alesander, now runs a free clinic in a small village not far from the excavation site.

To complicate matters, Corbett becomes involved with another member of his team, an attractive young graduate intern named Ella Beckwith. Meanwhile, as Corbett goes in search of Tariq, an ISIS sleeper cell begins to track him believing he will lead them to him.

Racing against time and the terrorists, Corbett must find Tariq and exfiltrate him before ISIS takes his head.