Some books open up whole worlds of which we were previously unaware, and Gainza's Portrait of an Unknown Lady did this for me. It's a kind of detective caper that purports to look into the life of a mysterious woman who was a master forger of the works of Mariette Lydis (real) in 'the golden age of forgery' in Buenos Aires in the swinging 60s. As part of Melancholical Forgers, Inc, Renee, the legendary forger, hung out with those who admired her and those who resented her for her beauty, brains, talent, and independence and she may even have been immortalized in a 1969 movie--which is also real! In fact, so many interesting real people and facts are mixed with the fictional that this phenomenal book is a kind of revolving door of fiction and fantasy. Once I started looking up some of the people mentioned, I was able to go down so many fascinating rabbit holes. I kind of want to read it again immediately because it is so craftily written, and I'm sure I'd catch more the second time through.