S2, E1: In a stretch of protected Amazon rainforest in Peru stands a 160-foot Brazil nut tree. Here, in one of the most bio-diverse regions on Earth, this 500-year-old titan thrives, thanks to alliances with some unexpected allies. Spend a year in the Tambopata National Reserve and meet the cast of characters that aid—and benefit from—the Brazil nut, from the forgetful agouti that plants its seeds throughout the jungle to the local harvesters that collect the nuts to the carpenter bees, the only creature strong enough to open and pollinate its flowers.