"The west door," the terrified creature muttered as he left the old man putting out the last remaining lights, and so made his way towards the exit indicated. "By the west door. It must needs be that. It is the nearest to the spot, and he will be there waiting for me, the moonlight shining in his glittering eyes as he beckons me to him, the glare of reproach in them. I must go. I must go." Down the long aisle he crept, shaking as with a palsy as he went, starting and almost crying out again as a bat flew by and brushed his hair with its wings, going onward to what he dreaded to see, the phantom of the murdered man which his distracted brain conjured up nightly. "He will be there," he muttered again. "He will be there." He reached the great west door--striking against the bell ropes hanging in the tower, and gasping at the contact--and then paused at the wicket let into the door, dreading to go out through it to meet the ghostly figure that he knew awaited him. Still, it must be done, and with another gasp, a smothered groan, he stepped out through the wicket into the shadow thrown by the cathedral wall, and gazed upon the moon-illuminated spot where Douglas had fallen dead. And once more he smothered a shriek that rose to his lips. Standing above that spot, its back to him, but as he could tell by the bent head, gazing down upon it, there was the figure of a man--a man still as death itself; a man bare-headed. "You have come again," he hissed in terror. "Again! Again! Mercy! Mercy!" Swiftly the figure turned and faced him--its eyes glistening in the moonlight as he had said--and advanced towards him. "Douglas!" he screamed. "Douglas! Mercy!" "No," the figure said. "No. Not Douglas. Archibald." CHAPTER XX. AVENGED. He had fallen grovelling to the earth as that figure turned its face towards him, and now he remained in the same position. As he did so Archibald Sholto knew for certain that he had found his brother's murderer. In the moment of witnessing that frenzied terror there had flashed into his mind the knowledge of who had been the wearer of the tiara with the one yellow-brown diamond in it; the recognition of the dark head streaked with grey with which his thoughts had been filled for weeks, yet without certainty--the head of the murderer's late mother! He knew all now. She it was who had worn the diadem in the great ceremonies he had taken part in; the rejoicings at the peace of '38, the almost equally great rejoicings at the death of the Emperor Charles, and many others. She, Lady Fordingbridge, his mother, had worn it often; often had he observed the strange light emitted by that blemished jewel; and now, from the tiara in which it still remained, a ruby was missing, and had been found on the spot where his brother had been done to death. Therefore he knew that that brother's assassin was before him. God had given him into his hands. He bent forward over the crouching creature at his feet; in a low voice he said: