Beneath the soil lies a world unseen, where threads of fungi weave silent partnerships with roots, shaping the destiny of plants, soils, and entire ecosystems. This book invites readers into that hidden realm of mycorrhiza, where science meets wonder, and ancient alliances continue to sustain life on Earth. The journey begins by uncovering what these remarkable fungi are, how they evolved, and the intricate structures that allow them to blend seamlessly with roots. Their story unfolds as more than biology; it becomes a narrative of resilience, showing how they fuel growth, deliver nutrients, draw water from the soil, and shield plants from the harsh trials of nature. But mycorrhiza are not only guardians of plants, they are caretakers of the soil. They stitch particles together into stable structures, keep nutrients in motion, nurture microbial communities, and guard against erosion, ensuring that the ground beneath us remains fertile and alive. Their influence extends further into human hands, where they support agriculture by improving yields, reducing dependence on fertilisers, strengthening organic farming, and enriching horticultural crops. Practical insights into the production and use of inoculants reveal how this hidden technology can be harnessed for nurseries, fields, and beyond. The vision expands to landscapes and forests, to restoration projects, and even to the frontier of biotechnology. With creativity and depth, this book presents mycorrhiza as more than fungi; they are nature’s living networks, quiet engineers of resilience, and essential allies for a sustainable future.