In the great cavernous place, with its choir beneath the dome, I heard low prayers in Latin. Men and women who passed me bowed and crossed themselves while many knelt. The glorious cathedral of Santa Maria del Fiore, so called from the Lily which figures in the Arms of Florence--hence "the Lily City"--had always an attraction for me, as it has for every visitor to the ancient Tuscan capital. The stained glass of Ghiberti, the wonderful mosaics of Gaddo Gaddi, the frescoes of angels by Santi di Tito, and the beautiful pictures by the great mediæval masters, all are marvellous, and worth crossing the world to see. From before the altar a long spiral mist of incense was rising, and about me as I stood in the centre of the enormous interior, many visitors were passing out from the dim religious gloom into the light of the open doorway. Suddenly my eyes caught sight of a countenance. I held my breath, standing rooted to the spot. What I saw staggered belief. Was it only a chimera of my unbalanced imagination--or was it actual fact? For a few seconds I remained undecided. Then, aghast and amazed, I became convinced that it was a stern reality. The mystery of the affair at Stretton Street became in that single moment a problem even more than ever bewildering. CHAPTER THE SIXTH ANOTHER PUZZLE Kneeling before Donatello's magnificent picture of the Virgin over one of the side altars, her outline dimly illuminated by the light of many candles, was a slim, dark-haired young woman in deep mourning. Her head was bowed in an attitude of great devotion, but a few moments later, when she raised her face, I stood rooted to the spot. The countenance was that of the dead girl Gabrielle Engledue! An involuntary exclamation left my lips, and a woman standing near me heard me, and wondered. Kneeling beside the girl in black was a thin-faced, black-haired Italian of about forty-five. He was somewhat handsome, though a sinister expression played about his lips. I watched the pair for several minutes, wondering whether in my brain, unbalanced as it had been, the scene was a mere chimera on my part and that, after all, the girl only slightly resembled the victim at Stretton Street. The latter I had not seen in life, and death always alters the features. Nevertheless, the sudden encounter was most startling, and from where I stood behind a great marble column I watched them. At last both rose and crossing themselves piously, walked slowly to the door. I followed them. It surely could not be that the girl whose death certificate I had forged, and whose body had been reduced to ashes, was actually alive and well! I recollected that sum of five thousand pounds, and the strange adventures which had befallen me after I had accepted the bribe to pose as a doctor, and certify that death had been due to natural causes.