Get the Summary of Brian C. Muraresku's The Immortality Key in 20 minutes. Please note: This is a summary & not the original book. Original book introduction: The most influential religious historian of the 20th century, Huston Smith, once referred to it as the "best-kept secret" in history. Did the ancient Greeks use drugs to find God? And did the earliest Christians inherit the same secret tradition? A profound knowledge of visionary plants, herbs,...