Living at the border between life and non-life, fungi use diverse cocktails of potent enzymes and acids to disassemble some of the most stubborn substances on the planet, turning rock into soil and wood into compost, allowing plants to grow. Fungi not only help create soil, they send out networks of tubes that enmesh roots and link plants together in the "Wood Wide Web." Fungi also drive many long-standing human fascinations: from yeasts that cause bread to rise and orchestrate the fermentation of sugar into alcohol; to psychedelic fungi; to the mold that produces penicillin and revolutionized modern medicine. And we can partner with fungi to heal the damage we've done to the planet. Fungi are already being used to make sustainable building materials and wearable leather, but they can do so much more. Fungi can digest many stubborn and toxic pollutants from crude oil to human-made polyurethane plastics and the explosive TNT. They can grow food from renewable sources: edible mushrooms can be grown on anything from plant waste to cigarette butts. And some fungi's antiviral compounds might be able to ease the colony collapse of bees. Merlin Sheldrake's revelatory introduction to this world will show us how fungi, and our relationships with them, are more astonishing than we could have imagined. Bringing to light science's latest discoveries and ingeniously parsing the varieties and behaviors of the fungi themselves, he points us toward the fundamental questions about the nature of intelligence and identity this massively diverse, little understood kingdom.