On sale for $2.99 is
Wild Bill Donovan: The Spymaster Who Created the OSS and Modern American Espionage, by Douglas Waller. The title pretty much says it; Donovan was America's top spook in WWII and the OSS was the precursor to the CIA. Available at
Kobo and
Amazon and presumably other (US at any rate) purveyors, since it's S&S. If you buy the Kindle version, you can add Audible for $3.99.
This was already on my wishlist, so I was glad to see the price reduction.