Convinced that they knew all about his smuggling business and would arrest him at the first opportunity, it made him so desperate that he would not have hesitated to kill both of them. He had not been standing at the head of the stairs long before he saw Harry glide into the hall as quietly as a shadow. The boy was becoming impatient over his partner's long absence and made up his mind to find him. Searching the lower hall, he failed to see anything of Old King Brady and then cautiously made his way upstairs. The Frenchman saw him coming. He slipped into the room where the old detective lay. Raising his finger to his wife, he hissed: "Hush! He coming up ze stair! Put out ze light--hurry!" Keeping the door open on a crack when darkness fell upon the room, he peered out and listened intently. It was too dark to see anything. But he heard the young detective's soft footfalls passing the door and he stepped out into the hall behind Harry. Slight as the noise was which he made, the boy heard him and turned around, striving to pierce the gloom with his sight. La Croix had the boy located. He suddenly sprang forward with both hands extended, struck against the boy, clutched him by the throat and knocked him over backward. A stifled cry escaped Harry. He was knocked down and struck the floor with a crash. As his head went back, with the Frenchman's grip on his windpipe, his skull banged against the door-casing. He was stunned. "Lena! Lena!" roared La Croix. "What is it, Paul?" asked the woman, appearing in the doorway. "Breeng a light--queek!" he panted. She struck a match and he saw that Harry was senseless. With a look of evil triumph on his dark face, the man seized the boy, dragged him into the room and his wife locked the door. La Croix bound and gagged Harry. "Got zem both!" he chuckled. "What are you going to do with them, Paul?" demanded his wife. "Do wiz zem? Put zem out of ze way, my dear. Dispose of zem so effectually zat we not weel be trouble wiz zem again." The woman met his evil glance and shuddered. She saw what murderous thoughts were filling his mind. CHAPTER VI. TWO MEN IN A BOX. On the following morning Paul La Croix went upstairs to the man who made artificial flowers and said to him: "Monsieur Reynard, to-day ve go avay to Europe. I 'ave some sings een ze rooms ve occupy zat I weesh to send to a friend een Sacramento. To do so, I must 'ave wong beeg packing case. I see an empty wong standing over zere near ze hatchway. Can I buy him from you?" "I'll make you a present of the big case, and be glad to get rid of it, as it takes up valuable space," replied Mr. Reynard, pleasantly. "Come, I'll help you to get it downstairs to your floor by means of the fall." He opened the hatchway while La Croix was profusely thanking him, put a sling around the box and lowered it. La Croix pulled the box into his front room through a door in the partition which surrounded the hatchway.