“The Yellow Room!” Who now remembers this affair which caused so much ink to flow fifteen years ago? Events are so quickly forgotten in Paris. Has not the very name of the Nayves trial and the tragic history of the death of little Menaldo passed out of mind? And yet the public attention was so deeply interested in the details of the trial that the occurrence of a ministerial crisis was completely unnoticed at the time. Now “The Yellow Room” trial, which preceded that of the Nayves by some years, made far more noise. The entire world hung for months over this obscure problem—the most obscure, it seems to me, that has ever challenged the perspicacity of our police or taxed the conscience of our judges. The solution of the problem baffled everybody who tried to find it. It was like a dramatic rebus with which old Europe and new America alike became fascinated. That is, in truth—I am permitted to say, because there cannot be any author’s vanity in all this, since I do nothing more than transcribe facts on which an exceptional documentation enables me to throw a new light—that is because, in truth, I do not know that, in the domain of reality or imagination, one can discover or recall to mind anything comparable, in its mystery, with the natural mystery of “The Yellow Room.” That which nobody could find out, Joseph Rouletabille, aged eighteen, then a reporter engaged on a leading journal, succeeded in discovering. But when, at the Assize Court, he brought in the key to the whole case, he did not tell the whole truth. He only allowed so much of it to appear as sufficed to ensure the acquittal of an innocent man. The reasons which he had for his reticence no longer exist. Better still, the time has come for my friend to speak out fully. You are going to know all; and, without further preamble, I am going to place before your eyes the problem of “The Yellow Room” as it was placed before the eyes of the entire world on the day following the enactment of the drama at the Château du Glandier. On the 25th of October, 1892, the following note appeared in the latest edition of the “Temps”:— “A frightful crime has been committed at the Glandier, on the border of the forest of Sainte-Geneviève, above Epinay-sur-Orge, at the house of Professor Stangerson. On that night, while the master was working in his laboratory, an attempt was made to assassinate Mademoiselle Stangerson, who was sleeping in a chamber adjoining this laboratory. The doctors do not answer for the life of Mdlle. Stangerson.”