I took the card she handed me, and started with mingled surprise and satisfaction when I recognised the name--Lady Pierrepoint-Lane. At last she was in London again! But how, I wondered had she discovered my whereabouts. Quickly I went into the hall, and there found her with blanched face and in a state of great agitation. "Ah, Doctor," she gasped breathlessly, as I greeted her and our hands met, "I am so glad I've found you? I went to Hammersmith, but your friend, Doctor Raymond, told me you were here." "What is the matter?" I inquired, surprised at her eager manner. "Has anything occurred?" "Yes, something most mysterious!" she answered hoarsely. "You are the only doctor whom I can trust. Will you come with me at once? I have a cab in waiting." "Where?" I inquired. "To your house?" "Yes," she urged. "Do not let us lose time. Apologise to your other patients here, and come at once. It's a matter of life or death." "Of life or death?" I cried. "Who is ill?" "It's all a mystery," she answered in the same breathless manner. "But you will keep it a secret--promise me." "I have many family secrets entrusted to me," I answered. "Rest assured that I shall betray no confidence." "Then come quickly, and recollect that what you may see or hear to-night you must never divulge. On your word of honour as a gentleman." "I give you my word of honour," I answered, wondering what fresh mystery was in store for me. Then, turning, I asked a servant, who stood near, to tell the patients waiting for me that I had been unexpectedly called out to an urgent case, and would return in an hour. "Good!" her ladyship exclaimed. "Let us not lose an instant." Instinctively I placed my instrument case in my pocket, and took down my hat. "Tell me the nature of the illness," I urged. "How did it occur? Who is the patient?" "How it occurred nobody knows. It is a mystery, as I tell you. My cousin Feo, to whom I think I introduced you, is dying!" "Dying!" I gasped, staring at her amazed. "Here in London?" "Yes, at my house. I have called you because you are a doctor, and I can rely upon your secrecy." CHAPTER SEVENTEEN. IN PERIL. Without loss of a moment we entered the hansom and drove along Bishop's Road and Westbourne Terrace, and thence across Sussex Gardens to Gloucester Square. Beside me my companion sat pale, erect, and rigid, responding only in monosyllables to my questions, and refusing to tell me anything beyond what she had already said--that her cousin was dying. Her manner was strange, as though she were in deadly fear.