"That might be a good way in which to catch a criminal," went on
Ned. "Often crooks call up on the telephone, but they know they
are safe. The authorities can't see them--they can only hear them.
Now if you could get a photograph of them while they were
telephoning--"

"I see!" cried Tom, excitedly. "That's a great idea! I'll work on
that, Ned."

And, all enthusiasm, Tom began to plan new schemes with his photo
telephone.

The young inventor did not forget his promise to help Mrs. Damon.
But he could get absolutely no clue to her husband's whereabouts.
Mr. Damon had completely and mysteriously disappeared. His
fortune, too, seemed to have been swallowed up by the sharpers,
though lawyers engaged by Tom could fasten no criminal acts on Mr.
Peters, who indignantly denied that he had done anything unlawful.

If he had, he had done it in such a way that he could not be
brought to justice. The promoter was still about Shopton, as well
groomed as ever, with his rose in his buttonhole, and wearing his
silk hat. He still speeded up and down Lake Carlopa in his
powerful motor boat. But he gave Tom Swift a wide berth.

Late one night, when Tom and Ned had been working at the new photo
telephone, after all the rest of the household had retired, Tom
suddenly looked up from his drawings and exclaimed:

"What's that?"