Description: The Teachings of the Master-Hearts explores a little-known esoteric tradition within modern Zoroastrianism known as Ilme K^ṣ^num. Through an innovative combination of historical analysis and translations of Gujarati texts, the book shows how Parsis in India have interpreted their religion in creative and diverse ways while responding to colonialism, modern science, and global exchanges. Focusing on the teachings of Behramshah Shroff and the mysterious figures known as the "master-hearts," author Mariano Errichiello reveals a rich world of spiritual ideas, practices, and debates. The book invites readers to see Zoroastrianism not as fixed and uniform, but as a dynamic tradition shaped by interpretation, imagination, and everyday life.