Throughout human history we've been too squeamish to take a closer look at our body's natural product. But as microbiologist Bryn Nelson suggests, we would spy a veritable cornucopia of possibilities in fecal matter, which can be used for medicine, sustainable power, and natural fertilizer to restore the world's depleted lands. Extolling the potency of poop, Nelson assesses how we can overcome our disgust and embrace our role as the producers of a more circular economy in which lowly byproducts become our species' salvation.