From amazon.com:

From #1 New York Times, #1 Wall Street Journal, and #1 Publishers Weekly bestselling author, Brad Thor, comes Blowback.

Scot Harvath’s counterterrorism career has just crashed and burned—thanks in part to a ruthless senator with her sights set on the White House. But when the war on terror takes a chilling turn, the president has no choice but to secretly bring Harvath back inside. Deep beneath an Alpine glacier, an ancient weapon designed to decimate the Roman Empire has been unearthed—and a shadowy organization intends to use it for America’s downfall. Racing across Europe, Harvath must secure the ultimate instrument of destruction before it brings the United States and the rest of the world to their knees.