As a tough but smart Italian American kid, Ernest Cuneo played Ivy League football at Columbia University and was in the old Brooklyn Dodgers NFL franchise before becoming a City Hall lawyer and "Brain Trust'' aide to President Roosevelt. He was on the payroll of national radio columnist Walter Winchell and mingled with the famous and powerful. But his status as a spy remained a secret, hiding in plain sight.

During this time, Cuneo began a love affair with one of Churchill's agents at Rockefeller Center--Margaret Watson, a beautiful Canadian woman with a photographic memory ideal for spycraft. In one nighttime attack, Watson was nearly smothered to death by a Nazi assassin inside her women's dormitory near Rockfeller Center. Cuneo's transformation from a gridiron athlete into a high-stakes intelligence go-between and political influencer is one of the great untold stories of American espionage. He has remained "invisible" in the public eye--until now, with this unveiled look into his life.

From the bestselling author and producer of the hit cable series Masters of Sex, Thomas Maier delves into the little-known tales behind FDR and Churchill; Canadian William "Intrepid" Stephenson, who oversaw the Rockefeller Center operation; the OSS's "Wild Bill'' Donovan and his in-house rival, Allen Dulles; and more. The Invisible Spy weaves Cuneo's remarkable personal story with the vivid and insightful portraits of many top figures in his world. Full of action and fascinating characters, this untold history shows how the British launched a far-ranging covert campaign against Nazi conspirators hidden in America, a spy war unbeknown to many.