A socialite is strangled to death in an unused storage closet within one of Manhattan's iconic hotels. Her murder puts the authorities on edge, but their concern turns into alarm when they spot a calling card on her corpse. The note confirms a sinister cult subdued many years ago has regrouped to try once again to crush the free world from within. Enter Dalton Lee, one of the world's pre-eminent architects. Twenty years ago, Lee brought the anarchists to their knees when he brilliantly deduced who among them had assassinated a congresswoman. With the group resuming its campaign of terror, the authorities recruit Lee and his staff to help them with the investigation, knowing they all now have a personal motive for finding the killer. Can Lee and his team figure out why the fringe group murdered the socialite - and who the murderer was - before New York is under siege and one of their own gets locked within the killer's crosshairs?