We live in an age of rising domestic terrorism. Much of this is a result of distortion of the truth and political twisting of data. Suppose, however, a compound could be used by extremists to change peaceful demonstrators into insurrectionists, removing the need for political persuasion.
Berserker is that deadly compound. Resurrected by a media magnate from an ancient Viking formula, it renders humans berserk.
Duncan MacGregor and his team must expose a plot to destroy American democracy, find the perpetrators. and disable them before they create overwhelming chaos.