As I entered the concierge met me with a note. It was from Harry Hambledon, written an hour before, urging me to meet him at the Gato Negro Café (The Black Cat), in the Calle del Principe. I lost no time in keeping the appointment, and on meeting my friend, he whispered excitedly: "Suzor has a visitor. He arrived at the Ritz at six o'clock, and they have dined together. He is a well-dressed man of between forty and fifty, rather sallow-faced, and has given his name at the hotel as Henri Thibon, rentier, of Bordeaux." "Aged nearly fifty--sallow?" I echoed. "Are his features of a rather Oriental cast--a dark, handsome man with deep-set eyes and a dimple in the centre of his chin?" I asked eagerly. "Yes. That just describes him." "De Gex!" I gasped. "Then he is here!" "After dinner they went out to the Trianon. They are there now." "Then we will watch them return to the Ritz," I said. We spent an hour together in the café, after which we rose and walked through the well-lit streets and along beneath the trees of the Prado until we came to the great plaza where, opposite the Neptune fountain, the fine hotel stands back behind its gardens. We both halted against the colossal fountain, the waters of which were plashing into the great basin, and found that from where we were standing we had a good view of the entrance to the hotel. That the theatres were over was proved by the number of cars and taxis that were depositing people in evening-dress who had come to the Ritz to supper. Hence we had not long to wait before we distinguished Suzor and his companion, both in dinner-jackets, strolling on foot across the Plaza from the Calle de Cervantes in the direction of the hotel. In an instant I recognized the form of the mysterious owner of the house in Stretton Street. "Yes!" I cried. "I'm not mistaken! But why is he here under the name of Thibon? Without a doubt he is known in Madrid. Why should he seek to conceal his identity?" "We are here to discover the motive of his journey from Italy. According to his passport he arrived from Irun. But if he had come direct from Italy he would have come from the south--from Barcelona, most probably." "He has a house in Paris. No doubt he has followed his friend Suzor from there. It will be interesting to watch." As I spoke the pair passed up the steps of the hotel and were lost to sight, therefore we turned and retraced our steps along the wide Carrera de San Jeronimo to my hotel where, for an hour, Hambledon sat in my room discussing the situation.