The latter went directly home, where he remained for nearly an hour. At the end of this time, he emerged from the house, much to the young detective’s relief. He had waited outside all this time, patiently watching for Felix’s reappearance.

Though cold and hungry, Bob could not afford to give up the chase long enough even to get a bit of lunch. He had made wonderful progress so far in his detective work, and he felt, as he had a right to feel, highly elated over his discoveries.

Now he was shadowing young Mortimer again. Down the Bowery they went till they came to a side street in a disreputable locality. Here they turned towards the East River, and presently Felix Mortimer left the sidewalk and disappeared within the door of an old building.

“So this is Gunwagner’s, is it?” said Bob to himself. “At least I s’pose ’tis, from what them fellers said—Gunwagner—yes, that’s the name. Well, this may not be it, but I’m pretty sure it is,” he continued, reasoning over the problem.

After fixing the house and its locality securely in his mind, and after having waited till he satisfied himself that Mortimer intended remaining there for a time, he made a lively trip to City Hall Park, where he joined young Flannery.

“Well, Bob, have you struck anything?” said Tom, instantly, and with much more than a passing interest.

“Yes; I’ve struck it rich—reg’lar detective style, I tell you, Tom,” said Bob, with pride and enthusiasm. And then he briefly related all his discoveries.

“Nobody could er worked the business like you, Bob,” said Tom, admiringly.

“Well, I did throw a little style into it, I think myself,” replied Bob. “But,” he continued, “there’s no time now for talking the matter over. We’ve got some work to do. I’ve got the place located, and I want you to go with me now, and see what we can do.”

Within five minutes the two boys were on their way to Christopher Gunwagner’s, and as they passed hurriedly along the streets they formed a hasty plan for immediate action—a plan cunningly devised for outwitting this miserable old fence and his villainous companions.