"There are a good many things that can go wrong," observed Ned. "The least little slip-up may spoil your traps, Tom."

"I know it, Ned. But I've got to take the chance. We've just got to do something for Mrs. Damon. She's wearing herself out by worrying," he added in a low voice, for indeed the wife of his friend felt the absence of her husband greatly. She had lost flesh, she ate scarcely anything, and her nights were wakeful ones of terror.

"What if this fails?" asked Ned.

"Then I'm going to work that button clew to the limit," replied Tom. "I'll go to Boylan and see what he and Peters have to say."

"If you'd done as I suggested you'd have gone to them first," spoke Ned. "You'll find they're mixed up in this."

"Maybe; but I doubt it. I tell you there isn't a clew leading to Peters--as yet."

"But there will be," insisted Ned. "You'll see that that I'm right this time."

"I can't see it, Ned. As a matter of fact, I would have gone to Boylan about that button I found in my airship only I've been so busy on this photo telephone, and in arranging the trap, that I haven't had time. But if this fails--and I'm hoping it won't--I'll get after him," and there was a grim look on the young inventor's face.

It was wearying and nervous work--this waiting. Tom and Ned felt the strain as they sat there in Mrs. Damon's library, near the telephone. It had been fitted up in readiness. Attached to the receiving wires was a sensitive plate, on which Tom hoped would be imprinted the image of the man at the other end of the wire--the criminal who, in exchange for the valuable land papers, would give Mr. Damon his liberty.

There was also the phonograph cylinder to record the man's voice. Several times, while waiting for the call to come in, Tom got up to test the apparatus. It was in perfect working order.