The second part of Percy Fawcett's story delves into his fascination with a document known as Manuscript 512 and how it impacted his life. His obsession led to his disappearance; there has been endless speculation about what exactly happened.
Research:

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25

Behind the Scenes Minis: Progressive Medicine
22:11