Irish-born and American-educated Sean Donovan is the NSA's favorite weapon when it comes to protecting the homeland. Losing his family to the Troubles in Northern Ireland showed him the dark realities of terrorism, and military training gave him the tools to fight it. When the threat of an attack on Portland, Oregon emerges from the haze of chatter, Donovan is sent to coordinate security. When all hell breaks loose, however, plans go out the window and an American city finds itself under siege. A worse threat appears lurking in the shadows of Portland's Underground, and a clock begins ticking. To what lengths will Donovan go to save the city? What will be left of Portland and, after all is said and done, what will be left of Donovan?