A maid answered their summons and led them to a reception-room.  A minute later one of the teachers appeared.

“Why, I thought you young gentlemen knew the young ladies had gone away,” said the teacher after they had mentioned the object of their visit.  “They said they were going to send you a note.”

“Gone away!” echoed Dick.

“Yes.  The three left for home on the late afternoon train.  Mrs. Stanhope and Mrs. Laning said it was a matter of business.  Then you didn’t get their note?”

“We did not,” answered Tom.

“That is too bad.  I am sure they spoke of sending it.  Wait, I will ask Parks, our messenger, about it.”

The teacher left the room, and the Rover boys looked speculatively at each other.

“They must have been getting ready to leave when Tubbs saw them,” said Dick.

“And we never knew they were going,” added Sam bitterly.

“The matter of business must refer to that Sobber case,” said Tom.  “I don’t know what else could take them home.”

“Maybe they have lost the case and must give the treasure up,” said Sam.  “In that case, Mr. Laning would have to take the girls away from such an expensive place as this.”

In a few minutes the lady teacher came back.

“Parks says he took three notes, addressed to Richard, Thomas and Samuel Rover.  He says he went over to Brill this morning with them and gave them to a man named Filbury.”

“Filbury, eh?” said Dick, naming an old man who worked around the dormitories.  “Well, we didn’t get them, and I am very sorry.”

“So am I, Mr. Rover,” said the teacher.

“Do you know how long the young ladies will be gone?”

“They could not tell.  They said they would send letters after they arrived home.”

This was all the seminary teacher could tell, and a minute later the Rovers said good night and left.  All hurried from the grounds in deep thought.

“We must find Filbury and see what he did with those letters,” said Tom, and his brothers agreed with him.

When they reached Brill they located the man they were after fixing a light in one of the halls.

“Where are those letters you got for us this morning, Filbury?” asked Dick sternly.

“Letters?” asked the old man, who was rather absent minded.  “I don’t remember no letters, Mr. Rover.”

“I mean the three letters which Parks of Hope Seminary gave you for me and my brothers.”

“Oh, them.  I remember now.  Let me see.  Yes, I got them, and one for Mr. Flockley, too.  I gave him all the letters.  He said he’d hand ’em to you.”  And apparently satisfied, Filbury resumed his work on the light.

“When was this?” demanded Sam.

“About eleven o’clock.  I hope it’s all right.  I would have delivered the letters myself, only I had a lot of work to do.”

“It is not all right, and we are going to look into the matter at once,” said Dick; and hurried off with Tom and Sam at his heels.  They went straight to the room occupied by Flockley and Koswell, and knocked on the door.  There was a stir within, a few whispered words, and then the door was opened.