"So much noise it would wake a tombstone," added Chet.

Again Jack called, and with no better results.

"Let's all yell together," suggested Joe.

This was done, but no answer came back.

"Sorry, but I've got a date elsewhere," mimicked Joe. "Be back next month at three o'clock."

"That fellow is no good, and I know it," murmured Frank. "An honest man would come back and face us."

"Listen!" cried Jack, putting up his hand.

All listened with strained ears.

"Don't hear a thing—" began Chet.

"I hear it," interrupted Frank.