A disturbing tape has made its way to British intelligence, and from them to the new President of the United States: battlefield chatter from an ambush in Afghanistan, in which twelve U.S. Army Rangers and a British medical team died. Most of the Taliban voices are Afghan; however, the voice of the commander bears an Irish accent. The idea that one of their own could be responsible for such a massacre is appalling, and Sean Dillon is put in charge of hunting the traitor.