(Sorry for the light posting. Was at a 2-day CLE on bankruptcy.)
The Lost City of Z: A Tale of Dealy Obsession in the Amazon, by David Graham.
Lost to the West: The Forgotten Byzantine Empire That Rescued Western Civilization, by Lars Brownworth.
The Lost City of Z is about British explorer Percy Fawcett, who disappeared in 1925 somewhere in the Amazon jungle looking for -- wait for it -- The Lost City of Z. A recent episode of Secrets of the Dead concluded he and his small, underfunded expedition were, basically, mugged by greedy locals. The finding was logical, if a little thin on the evidence, but there was more evidence for this finding than anything else.
Lost to the West has quickly become one of the classics of Eastern Roman (Byzantine) history. I was remiss in not getting it sooner.