Rain on the dead
(Book)

"In the past few years, the killing and capture of many al-Qaeda leaders has left the terrorist organization wounded--but by no means dead. And they intend to prove it. On a dark summer night, two Chechen mercenaries emerge from the waters off Nantucket to kill a high-value target, the former president of the United States, Jake Cazalet. Unfortunately for them, Cazalet has guests with him, including black ops specialist Sean Dillon and his colleague, Afghan war hero Captain Sara Gideon. The Chechens do not survive the night, but Dillon is curious as to how they even got on the island"--Dust jacket flap.