"I have that idea myself. You noticed that they were very particular to tell how the ransom money was to be delivered. That was quite an elaborate stunt, to have the money thrown off the train at a grade crossing. That would mean that the crooks could come along in a car, snatch up the package and be away without much risk of capture. They'd hardly go to the trouble of outlining all that if they didn't mean something by it."
"Yes, if the letter was only sent as a blind to bring dad back to Bayport you'd hardly think they'd go into all that detail."
"Still," Frank pointed out, "here we are, safe and sound. Haven't been kidnapped yet, and nobody has tried to kidnap us. If that letter had been sent to Chet's people, for instance, or to the Hoopers, they would have something to worry about." Suddenly he stopped and looked at Joe. "Say!" he exclaimed. "There's an idea!"
"What?"
"Chet and Biff!" declared Frank excitedly. "Don't you see? This may have something to do with them. Chet and Biff are missing. Perhaps they have been kidnapped."
"But why should any one kidnap them?" Joe looked wonderingly at his brother.
"In mistake for us. Don't you see it? Perhaps this gang mistook Chet and Biff for you and me and kidnapped them! Then they wrote the letter to dad."
"Gee, I never thought of that!" Joe exclaimed. "I'll bet dollars to doughnuts that you're right."
"Don't you remember the day we were all out in the boat and the three men came so close to us? Remember how closely they looked at Chet and Biff? Perhaps those fellows had been tipped off that you and I were in the boat and wanted to get a look at us so they could identify us when they got a chance to kidnap us. And instead of looking at us, they picked on Chet and Biff. They knew we owned a boat, but they wouldn't know that Biff had one. Therefore they'd think that the chap at the wheel would be either you or me."
"It hangs together, all right. And then, remember when we saw those same three men hanging around the Morton farm? They must have trailed Chet home to see where he lived. And all the time they thought he was either you or me!"