Then, feeling the wistful gaze of his worn and watery eyes upon our backs, we left the Mohave Scenic Studio forever. A run across town in my car brought us again to my door. My scrawny busybody of a maid opened it before I had opportunity to even draw forth my key. "Four or five telephone calls," she said with her impudent importance, "but only one is pressing." "One?" cried I, "who from?" "Somebody I don't know, Doctor. Margaret Somebody. She left a message. She wouldn't say no more than just one word." "What was that word?" cried Estabrook at my shoulder. "Danger." I suppose that both of us felt the shock and then the tingle of excitement in the meaning of that phrase, interpreted in the light of our understanding. "Doctor!" the young man shouted. "Yes, Estabrook," said I; "keep your nerve. I think I have the key to this problem in my possession. I have not yet explained. I did not want to do so unless it was necessary. But if I am right you must not weaken. You must be ready to throw your whole strength into loyalty and affection for your wife and courage to protect her at any cost!" "I'm ready!" he cried. "I feel that I must win her all over again. She is as fresh and new and beautiful to me as the day I first saw her. And I love her now as never before!" "Jump into the car, then!" I commanded, and turning to my chauffeur, whispered, "To the Marburys'. Where we were this morning. And what--we--want--is--speed!" He nodded, but I have no doubt that Estabrook and I both cursed him for his caution as he slowed down at the crossings, and finally, when, to conform to the traffic regulation, he circled in front of the banker's house. This time neither of us looked up at either residence, but ran forward toward the Estabrooks' door. I pressed the bell centred in the Chinese bronze. Suddenly, however, the unfortunate husband grasped the arm of my coat. "My promise!" he exclaimed. "You mean to keep it at any cost?" "Yes," said he. "I trusted her judgment and her loyalty, and gave her my word." "Pah!" I exploded angrily. His literal sense of honor, his narrow conscience which led him into inexpediency, seemed to me a part of a feminine rather than of a masculine nature, and more ridiculous than high-minded. "Well, wait here, then," I snapped back at him as Margaret Murchie opened the door. "If necessary I will call you." The old servant said nothing until we were in the hall, but her face was white with fear. I read on it the word she had transmitted to us by telephone. And whether or not it was my imagination, I felt the presence of a crisis and a forewarning that the inexplicable events which I had observed were now to come to some explosive end. Margaret's first words, said to me with her two large hands raised as if to ward off a menace, were not reassuring. "The scratching noise!" she cried. "The soft scratching noise!" I turned her toward me by grasping her shoulder.