In the hall-way Miss Saunderson, a typical Scottish housekeeper, stood beaming welcome; but in the very instant of greeting her, Robert Cairn stopped suddenly as if transfixed. Dr. Cairn also pulled up just within the door, his nostrils quivering and his clear grey eyes turning right and left--searching the shadows. Miss Saunderson detected this sudden restraint. "Is anything the matter?" she asked anxiously. Myra, standing beside Mr. Saunderson, began to look frightened. But Dr. Cairn, shaking off the incubus which had descended upon him, forced a laugh, and clapping his hand upon Robert's shoulder cried: "Wake up, my boy! I know it is good to be back in England again, but keep your day-dreaming for after lunch!" Robert Cairn forced a ghostly smile in return, and the odd incident promised soon to be forgotten. "How good of you," said Myra as the party entered the dining-room, "to come right from the station to see us. And you must be expected in Half-Moon Street, Dr. Cairn?" "Of course we came to see _you_ first," replied Robert Cairn significantly. Myra lowered her face and pursued that subject no further. No mention was made of Antony Ferrara, and neither Dr. Cairn nor his son cared to broach the subject. The lunch passed off, then, without any reference to the very matter which had brought them there that day. It was not until nearly an hour later that Dr. Cairn and his son found themselves alone for a moment. Then, with a furtive glance about him, the doctor spoke of that which had occupied his mind, to the exclusion of all else, since first they had entered the house of James Saunderson. "You noticed it, Rob?" he whispered. "My God! it nearly choked me!" Dr. Cairn nodded grimly. "It is all over the house," he continued, "in every room that I have entered. They are used to it, and evidently do not notice it, but coming in from the clean air, it is--" "Abominable, unclean--unholy!" "We know it," continued Dr. Cairn softly--"that smell of unholiness; we have good reason to know it. It heralded the death of Sir Michael Ferrara. It heralded the death of--another." "With a just God in heaven, can such things be?" "It is the secret incense of Ancient Egypt," whispered Dr. Cairn, glancing towards the open door; "it is the odour of that Black Magic which, by all natural law, should be buried and lost for ever in the tombs of the ancient wizards. Only two living men within my knowledge know the use and the hidden meaning of that perfume; only one living man has ever dared to make it--to use it...." "Antony Ferrara--" "We knew he was here, boy; now we know that he is using his powers here. Something tells me that we come to the end of the fight. May victory be with the just." CHAPTER XXI THE MAGICIAN Half-Moon Street was bathed in tropical sunlight. Dr. Cairn, with his hands behind him, stood looking out of the window. He turned to his son, who leant against a corner of the bookcase in the shadows of the big room.