"I'd just like to get a look at that machinery in the secret room the boy mentioned."
Frank was silent for a while.
"I wish Uncle Dock hadn't seen us there to-day. It'll make it awkward now if we ever go back. He has told us to stay away, and now he'll be suspicious if he ever sees us around there again."
"We might tell dad what we know about the place."
But Frank vetoed this suggestion.
"I'd rather work along our own lines until we get something more definite," he said. "If we get some real evidence we can tell dad about it. So far we have nothing to go on but our own suspicions."
All the way back to Bayport, the Hardy boys discussed the various aspects of the case, and although they agreed that the mysterious activities of the three men at the old mill tended to indicate almost anything but scientific endeavors, they realized that if they investigated too thoroughly they might get into serious trouble.
"We'll just wait a while and keep our ears open," Frank decided. "If those fellows are in the counterfeiting game they'll do something to give themselves away. And then we'll be right on the job."
When the boys arrived home they amused
