Cathedral by Nelson DeMille

St Patrick's Day, New York City. Everyone is celebrating but everyone is in for the shock of his life. Born into the heat and hatred of the Northern Ireland conflict, IRA man Brian Flynn has masterminded a brilliant terrorist act - the seizure of Saint Patrick's Cathedral. Among his hostages: the woman Brian Flynn once loved, a former terrorist turned peace activist. Among his enemies: an Irish-American police lieutenant fighting against a traitor inside his own ranks and a shadowy British intelligence officer pursuing his own cynical, bloody plan. The cops face a booby-trapped, perfectly laid out killing zone inside the church. The hostages face death. Flynn faces his own demons, in an electrifying duel of nerves, honor and betrayal...