At the conclusion of the novel, having left a long windrow of corpses in his wake, Khalil has narrowly escaped capture but promises Corey by telephone to return someday and kill him along with FBI agent Kate Mayfield, Corey's wife and partner.
"Yemen is a land of mistrust, which in a way removes any ambiguity," Harris tells Corey and Mayfield. "Trust no one and you won't be betrayed or misled. If a government official is assigned to assist you, he is not there to assist you. All informants lie, even the ones you pay. If an ordinary man begs you to get him a work visa to the States in exchange for information, he is working for the government or al Qaeda, and he just wants to get close to you and obtain your trust. Why? You'll find out the hard way. Any questions?"