The summer Hoyt Richards was 16, his family made their annual migration to Nantucket , where he spent long, unstructured days at Nobadeer Beach. It was there, on the pale sand, that Richards first encountered Frederick von Mierers: older, lean, striking, full of talk about Eastern philosophy, astrology , and the hidden architecture of the universe. Von Mierers threw parties nearby, nearly every night, and the teenage Richards came for the free beer, certain he was the one getting away with something. What he left with was the feeling that someone was paying attention—the very same vulnerability von Mierers would eventually exploit. Over the next two decades, von Mierers drew Richards into one of the most unlikely and revealing cult stories of the late 20th century.…