"Look here, Mike, I tell you again, I have an idea: I wonder if you will fall in with it. I have watched that fellow Gastrell pretty closely all the evening; I am rather a good judge of men, you know, and I believe him to be an impostor of some kind—I can't say just yet of what kind. Anyway, he is the man I met on the _Masonic_; he can deny it as much as he likes—he is. Either he is impersonating some other man, or some other man is impersonating him. Now listen. I am going to that address in Maresfield Gardens that he gave to his taxi-driver. I am going to find out if he lives there, or what he is doing there. What I want to know is—Will you come with me?" "Good heavens, Jack!" I exclaimed, "what an extraordinary thing to do. But what will you say when you get there? Supposing he does live there—or, for that matter, supposing he doesn't—what reason will you give for calling at the house?" "Oh, I'll invent some reason quick enough, but I want someone to be with me. Will you come? Will you or won't you?" I glanced up at the clock. It wanted twenty minutes to eleven. "Do you mean now? Do you intend to go at this time of the night?" "I intend to go at once—as fast as a taxi will take me there," he answered. I paused, undecided. It seemed such a strange thing to do, under the circumstances; but then, as I knew, Jack Osborne had always been fond of doing strange things. Though a member of Brooks's, he was unconventional in the extreme. "Yes, I will," I said, the originality of the idea suddenly appealing to me. In point of fact I, too, mistrusted this man Gastrell. Though he had looked me so straight in the eyes when, two hours before, he had calmly assured me that I was mistaken in believing him to be "his namesake in Geneva," as he put it; still, as I say, I felt convinced he was the same man. "Good," Osborne answered in a tone of satisfaction. "Come, we will start at once." A strange feeling of repressed excitement obsessed me as our taxi passed up Bond Street, turned into Oxford Street, then to the right into Orchard Street, and sped thence by way of Baker Street past Lord's cricket ground and up the Finchley Road. What would happen when we reached Maresfield Gardens? Would the door be opened by a stolid footman or by some frigid maidservant who would coldly inform us that "Mr. Gastrell was not at home"; or should we be shown in, and, if we were shown in, what excuse would Jack Osborne make for calling so late at night? I cannot say that I felt in the least anxious, however, for Osborne is a man who has knocked about the world and seen many queer sides of life, and who never, under any circumstances, is at a loss how to act. I glanced at my watch as our taxi turned into Maresfield Gardens. It was ten minutes past eleven. At the house indicated half-way up the hill the taxi suddenly pulled up.