"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?"
"Hiding, most probably," returned Billy.
"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."
"Oh, Jack, you may get in trouble."