Allen mines the American colonial period for his debut [The Shadow War], a complicated but intriguing thriller that posits an audacious and original conspiracy theory. Out of the blue, Library of Congress historian Benjamin Wainright receives a call from an old college roommate, Jeremy Fletcher, now a fellow at the prestigious and secretive American Heritage Foundation, who invites Benjamin to come to the think tank in western Massachusetts for reasons he won’t divulge over the phone. Benjamin arrives the next day to find Jeremy dead of a heart attack. Samuel Wolfe, a foundation “security analyst,” immediately enlists Benjamin’s aid in discovering why Jeremy, a nuclear war theorist, was interested in Benjamin’s area of expertise, the Puritan era. Their quest for answers takes them from the Berkshires to a forbidding underground nuclear missile base in Russia. …Allen keeps the action and the ideas flowing with commendable speed.