The fact was plain that Gabrielle Engledue, who had sent her luggage to the station cloak-room and was about to return to Madrid, was killed, probably by the scratch of a pin upon which orosin had been placed. "All this is most astounding," declared Superintendent Fletcher. "Of course, De Gex contrived that no inquiry would be made concerning the dead girl. He might have shown you the body of Miss Engledue, but he had some motive in keeping it from you, and obtaining a death certificate for the girl who was still living." "The motive was that he was not quite certain whether the orosin could be detected. Since then he has grown bolder, as witness the murder of the Baron van Veltrup," I replied. "But why should he not have shown you the dead girl?" queried the Superintendent. "Because he no doubt wished to mystify me in case of my recovery from the effects of the drug," was my reply. "He was not quite certain of the effect that the dose might have upon me, so in order to entirely mislead me, so that if I recovered my statements would be discredited, he showed me a girl who was still living, though to all intents dead. Indeed, I have come to the conclusion that, aided by Moroni, he purposely contrived that I should meet and recognize in Miss Tennison the girl I had been told was the dead girl Gabrielle Engledue. And I confess that I have been sorely puzzled all along that the girl whom I had seen dead was actually alive, even though her mental state was such as to show that she had met with foul play." "Yes," remarked Rivero. "The plot was very cunningly conceived, especially the manner in which you were entrapped and induced to give the certificate." "Here is the money which De Gex gave me for my share in the crime," I said openly, laying the bank notes upon the Superintendent's table. "I suppose some action will be taken against me, but I am prepared to take the consequences, now that I have unmasked one of the greatest and most dangerous criminals of modern times." "You certainly have done that, Mr. Garfield," remarked Superintendent Fletcher. "And I venture to think that the part which you have played in solving this problem will be taken into account when your own actions are considered." "It seems to me," remarked Rivero, "that the reason the poison-maker, Moroni, evinced such a keen interest in Miss Tennison, and his reason for taking her to a number of specialists was solely in order to gain their opinions and so further study the effects of the deadly drug which he prepared." "I have learnt," I said, "that Moroni was the laboratory assistant of the late Professor Orosi, the discoverer of the drug." "Ah! Then of course he knows the secret of its preparation, how to administer it, and in what doses," remarked Fletcher.