India, April 28 -- For Ruby Lal, the tale begins when she stumbles upon a rare book in a Delhi market, in 1996. It is a 1902 translation of Ahval-e Humayun Badshah, popularly called the Humayun-nama, an account of the emperor Humayun's life and reign. Few people know that it was written by a woman, Gulbadan Begum, Humayun's half-sister....