"Na Hanyate Hanyamane Sharire -The Secret of Immortality" is a profound and thought-provoking journey that bridges modern science with ancient Indian spiritual wisdom. Through the story of Dr. Ravi, the book explores the human quest for immortality beginning in the AI and biotech laboratories of Silicon Valley and gradually leading toward yoga, the Upanishads, and self-realisation. Alongside themes such as longevity science, cellular reprogramming, and human optimisation, the narrative unfolds the essence of Patanjali's Ashtanga Yoga, meditation, and the eternal nature of consciousness in a simple yet deeply reflective manner. Ultimately, the book leads the reader to a timeless Upanishadic truth: true immortality does not lie in preserving the body, but in realising that consciousness exists beyond it, "Na Hanyate Hanyamane Sharire." This book is for readers who seek to understand the mysteries of life, death, and consciousness through both scientific and spiritual perspectives.