The boys read the letters and documents with interest.  From them they learned that Mr. Rover had been requested to come to the city immediately, to see about some business connected with the Sunset Irrigation Company.  The documents were some transfers of stock which they did not quite understand.

“He came down here to see Pelter, Japson & Company, that’s certain,” remarked Dick.  “It eras evidently the only reason why he came to New York.  Now the question is, Did he go and see those men, and did they waylay him, or did they hire somebody to do it?”

“I wish we knew more about those men,” said Tom.  “You can soon size a fellow up when you talk to him.”

“Not always,” answered Sam.  “Sometimes the smoothest talkers are the greatest rascals.  Don’t you remember how nicely Josiah Crabtree used to talk to Mrs. Stanhope, and see what a rascal he turned out to be!”

“I wonder if they have captured him yet,” mused Tom.

“Never mind Crabtree now,” put in Dick.  “What we want to do is to find father.  I don’t know exactly how we are going at it, but I think I’ll have some sort of plan by morning.”

“We can go down to Pelter, Japson & Company and make them tell what they know,” said Sam.

“They’ll tell what they feel like telling, Sam,—­ and that might not do us any good.  Mind you, I don’t say they did father any harm.  But I know they didn’t like the way he was getting after them, for they knew that, sooner or later, he might sue them and possibly put one or more of them in jail for fraud.”

For fully an hour the boys talked the situation over, and by that time Sam was so sleepy he could scarcely keep his eyes open.  Then they retired, Dick remaining in the apartment his father had occupied, and Sam and Tom taking the next room.

For over half an hour Dick turned and tossed on the bed—­ his mind filled with thoughts of his father.  What had become of his parent?  Had he been hurt, or killed, or was he being held a prisoner by his enemies?  What if his father should never be heard of again?  The last thought was so horrible it made the youth shiver.

“We’ve got to find him!” he murmured, as he drew the bedclothes around him.  “We’ve got to do it!”

At last Dick fell into a troubled sleep, following the example of his brothers, who had also found difficulty in settling themselves.

Presently the oldest Rover boy awoke with a start.  He sat up in bed, wondering what had thus awakened him.

From the next room came the regular breathing of Sam and Tom, showing that they were still in the land of slumber.  Dick listened, but no unusual sound broke the stillness.

“It must have been my nervousness,” he thought.  “Father’s disappearance has been too much for me.  Well, it’s enough to get on anybody’s nerves.”

He prepared to lie down again, when a faint scraping sound caught his ear.  He listened intently.