“My!  I never supposed newspaper work was so complicated,” said Grace, with a little sigh.  “Now let’s go to the detectives.  I’m almost afraid.  It sounds so awful to say ‘detective.’”

Larry found the man he knew in the office of the agency, and the latter introduced him to the chief.  The reporter explained the reason for the visit, and Grace added a plea that they do all in their power to locate Mr. Potter.

“I thought you’d come here sooner or later,” said the chief with a smile.  “Most folks do when they find the regular police don’t give enough attention to the cases.  It’s not the fault of the police, though.  They have so much to do they can’t give much time to a single case.  But of course we can.  Now then, tell me all about it.”

Which Grace, aided by Larry, proceeded to do.  The chief listened intently, and asked several questions.  He took the two letters which Grace had from her father and looked carefully at them.

“Do you think you’ll be able to do anything?” asked the girl anxiously.  The strain was beginning to tell heavily on her.

“Of course we will!” exclaimed the chief, heartily.  “We’ll find your father for you, you can depend on it!”

Larry did not want to tell her that the chief was thus optimistic in regard to every case he undertook.  It was a habit of his, not a bad one, perhaps, and it did little harm, for nearly all of his clients wanted cheering up.

“What do you think about this, young man?” asked the chief, turning suddenly to Larry.

“In regard to what, Mr. Grover?”

“Where do you think Mr. Potter is?  I understand you’ve been working on this case.  In fact, I have all your stories clipped from the Leader.”

Larry had not forgotten about Retto, and he determined to pay the fellow another visit.

With him, to think was to act.  He soon found himself going up the stairs of the tenement house, and presently reached Retto’s door.  His knock brought no response, and he stood for a moment, undecided what to do.  Then a bold idea came to him.

“I’ll try the door and see if he’s home,” he said.  “If he isn’t, there’s no harm done.  If he is, I can explain it somehow.”

Larry, after a moment’s hesitation to listen for any possible movement on the other side of the portal, tried the door.  It opened easily for him, though it needed but a glance to show that the apartment was empty and vacated.  All the furniture was gone.

“He’s skipped!” exclaimed Larry, as he struck a match and looked around.  “I guess he was afraid I’d find him.  Well, I am more determined than ever that I’ll land this man.  I wonder if he left any clues behind?”

He lighted a jet of a wall fixture, for the gas had not been shut off.  In the glare he saw a scrap of paper lying on the floor.  He picked it up.  As he glanced at it he gave a cry of astonishment.

“Who would have thought it!” exclaimed Larry to himself.  “Of all the strange things!  I wonder I didn’t connect him with the case before!  This explains why he was in front of the house.”