"Glad to have you," was the rejoinder. Talking and laughing merrily over old times on the _Tropic Queen_, the boys walked on, not noticing much where they were going till they found themselves on an ill-lighted street of rather shabby-looking dwellings.
"Hullo," said Ned, "I don't think much of this part of town. Let's get back to a main street."
"It's a regular slum," said Billy, and the three boys started to retrace their steps. But suddenly Jack stopped and jerked his companions into a doorway. Two figures had just come in sight round the corner. They were headed down the street on the opposite sidewalk.
"It's Judson and his son," whispered Jack. "What can they be doing here?"
"Yes, they--hullo! Look, they're going into that alley-way."
The boys darted across the street. Looking down the alley-way, they saw the figures of Judson and his son, by the light of a sickly gas lamp, ascending the steps of a rickety-looking tenement house.
"Jove, this is worth knowing," exclaimed Jack. "If they are really hiding here we can get the police on their track. How lucky that we just let ourselves roam into this part of town."
"We ought to have them arrested at once," said Billy.
"Yes, that's a good idea. But they may have just sneaked through the hallway and out by a rear way. You fellows wait here till I go and see."
"No, you stay here," Jack insisted. "One of us won't be noticed. Three would. Besides, that house is full of other tenants. Nothing much could happen to me."
In spite of their further protests he walked rapidly, but cautiously, down the alley-way. Noiselessly he entered the hallway and walked to the door of a rear room, where he heard voices. But it was a laboring man and his wife quarreling over something. Jack heard a door open on an upper floor. Then came a voice that thrilled him. It was Jarrow's.
"Hullo, Judson, back again? Well, how did things go?"
Then Jack heard the door closed and locked.
"So, they are really here," he muttered. "What a piece of luck. But the question is, have they got the code? If it is out of their hands it will be well nigh impossible to recover it, for it is a serious matter to charge an ambassador with wrong-doing."
Jack began to ascend the rickety stairs with great caution. They creaked dismally under his tread. At a door on the second floor he caught the sound of Judson's voice. With a beating heart he crept as close as he dared and listened.