This book is the biography of the Twelfth Imam, Imam Muhammad al-Mahdi (a.s.), also referred to as the Qaim of Aale Muhammad, the Awaited Imam (a.s.) and the Last of the Successors. The book also covers major objections that the opponents of Shias aim against the belief in Imam Mahdi (a.s.), which the respected author, Baqir Sharif Qarashi has refuted in a convincing way.