When they arrived at the farm they found that their uncle had sent a long letter to the officers of the traction company, relating in full what had occurred. In return the officials of the concern said they would put a private detective on the case, and this was done. But weeks went by and nothing was seen or heard of Merrick and Pike, and what had become of the missing bonds remained a mystery.
"I am anxious to take a look at that cave where the stolen freight was stored," said Sam one day. "Supposing we drive to it?"
"That will suit me," answered Dick. "I want to learn about something else--that red tin box I saw hanging from a tree."
"Oh, yes, I had forgotten about that," put in Tom. "Well, shall we walk or drive over?"
It was decided to drive as far as the cave, and not knowing how long they would be gone, the boys took a lunch along.
"Now, take care of yourselves," warned Randolph Rover. "Don't fall into any more holes."
Then Dick cracked the whip, and off the team started at a good pace, the eldest Rover, however, holding them well under control. It was a clear and beautiful day. The boys did not dream of the odd adventure in store for them.
"It won't be long now before we'll have to get back to Putnam Hall," observed Sam, as they drove along. "Dear old school! How I love it!"
"It's too bad that we are getting too old to go there," said Tom. "But we can't be boys always."
"I shall be glad to see the other fellows again," came from Dick.
"Do you know what I think?" declared Tom. "I think the Putnam Hall cadets are the finest lot of boys in the world!"
"Throwing bouquets at yourself, Tom?" said Sam, with a laugh.
"I certainly do, Sam, and Captain Putnam is the best teacher in the world. My, but won't we have fun when we get back!"
"We'll have to have a feast in honor of our return," said Dick, and smiled that quiet smile of his which meant so much.
The distance to the cave was soon covered, and the boys tied their team to a tree in that vicinity. They went inside and found that everything, even to the empty boxes, had been taken away. The place had been explored by a number of curiosity seekers.
"It is queer that this cave wasn't discovered before," was Dick's comment, after they had spent half an hour in walking around.