When we think of fungi, we probably think of mushrooms. But mushrooms are only fruiting bodies, analogous to apples on a tree. Most fungi live out of sight, yet make up a massively diverse kingdom of organisms that support and sustain nearly all living systems. The more we learn about fungi, the less makes sense without them. Sheldrake’s mind-bending journey into this hidden world ranges from yeast to psychedelics, to the fungi that sprawl for miles underground and are the largest organisms on the planet, to those that make all plant life possible, to those that infiltrate and manipulate insect bodies with devastating precision.