Dr. Cairn had not yet dismissed the last of his patients; Myra, accompanied by Miss Saunderson, was out shopping; and Robert found himself compelled to possess his soul in patience. He paced restlessly up and down the library, sometimes taking a book at random, scanning its pages with unseeing eyes, and replacing it without having formed the slightest impression of its contents. He tried to smoke; but his pipe was constantly going out, and he had littered the hearth untidily with burnt matches, when Dr. Cairn suddenly opened the library door, and entered.
"I have tracked him, sir!" he cried. "My God! while Myra was at Saunderson's, she was almost next door to the beast! His den is in a field no more than a thousand yards from the garden wall--from Saunderson's orchid-houses!"
"He is daring," muttered Dr. Cairn, "but his selection of that site served two purposes. The spot was suitable in many ways; and we were least likely to look for him next-door, as it were. It was a move characteristic of the accomplished criminal."
"It is the place of which Myra dreamt, sir. I have not the slightest doubt about that. What we have to find out is at what times of the day and night he goes there--"
"I doubt," interrupted Dr. Cairn, "if he often visits the place during the day. As you know, he has abandoned his rooms in Piccadilly, but I have no doubt, knowing his sybaritic habits, that he has some other palatial place in town. I have been making inquiries in several directions, especially in--certain directions--"
He paused, raising his eyebrows, significantly.
"Additions to the Zenana!" inquired Robert.
"Exactly," he replied. "There is not a scrap of evidence upon which, legally, he could be convicted; but since his return from Egypt, Rob, he has added other victims to the list!"
"The fiend!" cried the younger man, "the unnatural fiend!"
"Unnatural is the word; he is literally unnatural; but many women find him irresistible; he is typical of the unholy brood to which he belongs. The evil beauty of the Witch-Queen sent many a soul to perdition; the evil beauty of her son has zealously carried on the work."
"I doubt if we can do anything to-day. Obviously the early morning is the most suitable time to visit his den at Dulwich Common."