There was a click, that told of a receiver being placed back on
the hook, and the voice ceased. So, also, did the queer, buzzing
sound over which Tom puzzled.

"What can it have been?" he asked. "Did you hear it, Mrs. Damon?"

"What, Tom?"

"That buzzing sound."

"Yes, I heard, but I didn't know what it was. Oh, Tom, what shall
I do?"

"Don't worry. We'll see if anything happened. They may have caught
that fellow. If not I'll plan another scheme."

Tom's first act was to call up the telephone exchange to learn
where the second call had come from. He got the information at
once. The address was in the suburbs. The man had not gone to the
drug store this time.

"Did the detective get out to that address?" asked Tom eagerly of
the manager.

"Yes. As soon as we were certain that he was the party you wanted,
your man got right after him, Mr. Swift."

"That's good, I hope he catches him!" cried the young inventor. "We'll
have to wait and find out."