“I daresay you are right,” answered he with a slight sneer. “Thank you,” returned Mascarin coolly. “At any rate, I was deeply interested in solving this riddle, the more as I belonged to an association which owes its being and position to its skill in penetrating the secrets of others. I shut myself up in my room, and vowed that I would not leave it until I had worked out the cipher.” Paul, Hortebise, and Catenac examined the letter curiously, but could make nothing of it. “I can’t make head or tail of it,” said the doctor impatiently. Mascarin smiled as he took back the paper, and remarked,-- “At first I was as much puzzled as you were, and more than once was tempted to throw the document into the waste-paper basket, but a secret feeling that it opened a way to all our fortunes restrained me. Of course there was the chance that I might only decipher some foolish jest, and no secret at all, but still I went on. If the commencement of the word was written in a woman’s hand, the last word had evidently been added by a man. But why should a cryptogram have been used? Was it because the demand was of so dangerous and compromising a character that it was impossible to put it in plain language? If so, why was the last word not in cipher? Simply because the mere rejection of what was certainly a demand would in no manner compromise the writer. You will ask how it happens that demand and rejection are both on the same sheet of paper. I thought this over, and came to the conclusion that the letter had once been meant for the post, but had been sent by hand. Perhaps the writers may have occupied rooms in the same house. The woman, in the anguish of her soul, may have sent the letter by a servant to her husband, and he, transported by rage, may have hurriedly scrawled this word across it, and returned it again: ‘Take this to your mistress.’ Having settled this point, I attacked the cipher, and, after fourteen hours’ hard work, hit upon its meaning. “Accidentally I held the piece of paper between myself and the light, with the side on which the writing was turned from me, and read it at once. It was a cryptogram of the simplest kind, as the letters forming the words were simply reversed. I divided the letters into words, and made out this sentence: ‘_Grace, je suis innocente. Ayez pitie; rendez-moi notre enfant_ (Mercy, I am innocent. Give me back our son).’” Hortebise snatched up the paper and glanced at it. “You are right,” said he; “it is the art of cipher writing in its infancy.”