"Well, Hugh," he said, "we now know the truth, and it remains for us to combat the fiends. If you are marked down--no doubt I am also. So it behoves us both to be very wary." "Why can't we tell the police the whole circumstances?" I suggested. "My dear fellow, they wouldn't believe you, and they wouldn't arrest such a powerful man as Oswald De Gex," was his serious reply. "Money can buy immunity from arrest in every country in Europe, and especially De Gex's money, for it can be distributed in secret by his agents. No. If we are to be successful we must lay our plans just as cleverly as he lays his. We must allow him to believe that we are entirely unsuspicious of his plotting. That is our only way." I realized that there was much truth in his argument. It remained with us to pretend ignorance. Therefore we resolved to still watch and wait. A few hours later I told Señor Andrade, the Chief of Police, of the professor's discovery that the points of the pins had been infected with orosin, the newly discovered drug which in small doses produced loss of memory and insanity, and in larger doses sudden death. In reply, he informed me that though every effort had been made to trace the elusive fugitive, all had been in vain, and that he was still at large. "But if he has this terrible drug in his possession he is more than ever a danger to society," the Spanish official went on, speaking in French. "I thank you, m'sieur, for all the information you have given me, and you may rely upon me to take every possible step towards securing his arrest. I was in telegraphic communication with the Paris Sûreté only this morning concerning him. I will wire them again. They have been stirred into activity by the message I sent them after your call to see me." I longed again to be frank with the affable Señor Andrade, yet I saw that if I were I might negative all chance of solving the problem which concerned the health and life of the girl whom I had grown to love so fervently. Upon a sudden impulse I remarked with affected carelessness: "I hear that our English financier, Mr. De Gex, is at the Ritz." "Yes," he replied. "He is here under an assumed name in connexion with some big railway scheme in Estremadura--a line between Toledo and Merida. It is badly wanted, and has been talked of for years. There is a huge stretch of country south of the Tagus as far as Villa Nueva without any railway communication. The King himself has been agitating for the development of that rich agricultural region for the last ten years. And now it seems as though your great financier, Monsieur De Gex, is here to consult with the Ministry of Communications." "Yes," I said, realizing in what high esteem that mystery-man of millions was held.