This is a strange, complex and triumphantly confident reimagining of Joseph Conrad's Heart of Darkness for a different age. Marina Singh, a docile lab rat, must follow her former mentor Dr. Annick Swenson into the sweaty and uncomfortable depths of the Amazon jungle, whence Swenson has vanished in search of the secret to a mysterious fertility drug. Singh finds her living with a bizarre indigenous tribe, but from there the mystery only deepens — Swenson's methods are, as the saying goes, unorthodox. It's an extraordinary pleasure to go on a journey like this, into the verdant chaos of the Amazon with an orderly, sane, exquisitely sensitive observer like Ann Patchett as your companion. The stakes are different from what they were in Conrad's day, but now, as then, the journey is as much an inner one as an outer.