I've read some of Ann Patchett's books before and loved them. Bel Canto, Truth and Beauty, Run: all are gorgeous and sad and slyly shocking in different ways. But something about this one, set mostly in the Amazon, of all places, just killed me. I'll leave the plot summary and professional analysis to others. Let me say how beautiful and simple her writing is, how well drawn her characters, how crazy and moving her story. There's a not-quite-cheesy thriller element (we're in the jungle, and yes, there are anacondas and cannibals); it's handled tastefully but still totally suspenseful. This short conversation between Patchett and her good friend Elizabeth Gilbert (of Eat, Pray, Love fame) is charming, too.
ps: David Grann's The Lost City of Z is another Amazon book. This one is nonfiction—and also an amazing story that's fantastically well written.