Before leaving the house he did one thing more to allay his fears. He called up a private detective bureau and ordered them to keep watch of the house night and day until further notice. They were to keep their eyes open for any slightly deranged person who might seek an entrance. In the event of capturing him, they were to take him into the house and put him to bed, remaining at his side until he, Donaldson, arrived. Then he ordered his cab to the restaurant of Wun Chung. CHAPTER XV _The Derelict_ Chung had news for him; he had not yet found Arsdale, but his men reported that yesterday the boy had been concealed at Hop Tung's, where Saul had first suspected him to be. The evil-eyed proprietor had hidden him, half in terror of Arsdale himself and half through lust of his money. Finally, however, fearing for the young man's sanity he had thrown him out upon the street. It would go hard with the yellow rat, Chung declared, for such treachery as this to the Lieutenant. "It may go hard with all of you," replied Donaldson significantly. "But you 've another chance yet; the boy is back here somewhere. Find him within twenty-four hours and I'll help you with Saul." "He clome black?" exclaimed Chung. "Sometime early this morning." If the boy was in the neighborhood, Chung asserted eagerly, he would find him within an hour or hang the cursed-of-his-ancestors, Tung, by his pigtail from his own window. "Which is better than being locked up in jail. Are you children," Donaldson exploded, "that you can be duped like that?" Chung appeared worried. But his slant eyes contracted until scarcely more than the eye-lashes were revealed. However inactive he may have been up to now, Donaldson knew that an end had come to his sluggishness. When Chung left the room there was determination in every wrinkle of his loose embroidered blouse. So there were some nooks in Chinatown, mused Donaldson, that even Saul did not know. The longer he sat there, the more indignant he became at the treachery of this moon-faced traitor who was indirectly responsible for the nightmare through which the girl had passed. Yet, as he realized, no more responsible than he himself. He had been a thousand times more unfaithful to the girl than Tung had been to Saul. Chung returned with a brew of his finest tea. He was loquacious. He tried one subject after another, interjecting protestations of his friendship for Saul. Donaldson heard nothing but the even voice and the sibilant dialect. He seemed chained to that one torturing picture. Even the prospect of finding the boy and so ending the suspense which had battered Miss Arsdale's nerves for so long brought little relief. He never could be needed again as he had been needed then. He might even have been able to detain Arsdale and so have avoided this present crisis. He felt all the pangs of an honest sentry who, asleep at his post, awakes to the fact that the enemy has slipped by him in the night.