Certainly matters had now assumed a very critical aspect. I hurried out along the broad, tree-lined Paseo, where the moon was now shining brightly over the Bay of San Sebastian, to the Hotel Continental. Here the gold-laced _concierge_ told me that Madame Tavernier had left about an hour before. "Did she say where she was going?" I inquired. "Yes, to Santander," replied the _concierge_; "the Hotel Europa she gave as her address, so that we might forward her letters; she said she had not expected to leave so soon." The meaning of the visiting-card was now plain. Evidently the resourceful Madame Gabrielle had made some important discovery. She dared not communicate with me, but, of course, she knew I would make inquiries, and for this reason she had left her address with the hotel porter. But why had she gone to Santander? Cost what it might, I must find the answer to that question. "What about the gentleman who was with her?" I asked the porter, making a blind shot to try to find out something. "Gentleman?" he queried. "Madame was alone in the omnibus except for an Italian gentleman, who went to catch the same train to Bilbao." "An Italian gentleman!" I echoed. Here might be the key to the mystery. "He was about forty--pale, with a dark-cropped moustache and rather bald--eh?" "Yes," replied the man, "that is Signor Bruno." "What about his friend?" I asked. "He left for Madrid by the early train this morning," was the reply. Matters were now becoming clear. Evidently the second "Italian" had cleared off, leaving "Signor Bruno" in charge of the developments of the plot. I had now to find "Bruno," and through him to get on the track of "Fontan." Pleased with my success, I slipped a few pesetas into the willing hand of the _concierge_ and left the hotel, directing my steps back to the Ezcurra. Why had Madame Gabrielle left for Santander when obviously San Sebastian was the real centre of the plot? The cryptic telegram I had received told us that. It was, in fact, a spy message sent from Holland, which had been intercepted by the French Secret Service and duplicated to me; the real message, of course, had been duly handed to "Fontan" at the post office in San Sebastian. How to get to Santander was now the problem. The last train had gone. But after half an hour's deliberation I hit upon a plan which at least held out a good promise of success. I returned to my hotel and gave strict orders that, as I was not feeling well, I was on no account to be disturbed until noon the following day.