It’s a savage journey that takes Mark from Los Angeles to the Amazon — through Mexico and Guatemala and Honduras, through Nicaragua and Costa Rica and Panama, through Colombia and Ecuador and Peru. On his ride into the dark south of the Americas: a failed revolution, a spewing volcano, a drawer of cocaine; and a surreal succession of encounters with an assortment of characters normally avoided — Scientologists and shamans and narcos. He risks his freedom, his sanity, his life. By the end, he at last finds a point to it all: he goes far to find…