We follow here step by step the literary investigation full of twists of Nader Nasiri-Moghaddam. Discovering in an issue of the Review of Two Worlds the play "The Court of Tehran or Do not wake the sleeping cat" signed "Haçan Mehemet Khan", obviously a pseudonym, he makes all kinds of assumptions about its author, which leads him to the first teacher of French at the Polytechnic School of Tehran, Jules Richard. He has written a diary, unfortunately lost, of which only fragments are preserved of his translation into Persian. In this journal, Nader Nasiri-Moghaddam finds some similarities with the content of the play. Convinced that he had solved the enigma, he went to the Bibliothèque Sainte-Geneviève to consult again the volume VII of the Revue des Deux Mondes containing the piece, but he was mistakenly given the volume that contained the general table of the aforementioned journal for the period from 1831 to 1874. And to his surprise, he discovers that the real author of the play is Etienne Gilbert Eugène de Sartiges. The play is given in French, in a commented edition, and in its Persian translation. What also appears in the book is the facsimile of his edition in the Revue des Deux Mondes. Nader Nasiri-Moghaddam completes the reader's vision of the time, that of Mohammad Shah Qajar's (1834-1848), by giving the reader access to the translation in Persian, and in its reconstituted French version, the Diary of Jules Richard. The general introduction of the book is also translated into Persian. The first part of the book is devoted to texts in French and the second (to be read in reverse) to texts in Persian.