NCIS Special Agent Linus Schag is no stranger to violence and bloodshed, but when he’s sent to Iraq to take custody of two Navy SEALs suspected of murder, he finds himself thrust into a manmade inferno as coalition forces fight to free northern Iraq from the Islamic extremist group called ISIS.

The explosion of an IED allows the SEALs, suspected of killing a fellow commando, to escape and flee up the Tigris River in a stolen Navy patrol boat. Schag pursues the SEALs in another boat assisted by an Army criminal investigator, a vengeful Iraqi interpreter, and a hostile Navy boat crew. Facing danger at each bend in the river, Schag and his companions endure ambushes, firefights, and friendly fire as he tries to discover the secret that lures the SEALs straight into the dark heart of an ISIS-made hell on earth.