"I wonder what's become of that bum detective?" asked George after a short silence. "We heard him rowing along in front of us one minute, and the next minute there wasn't a single sound to indicate that there was another boat in the mine."
"As soon as I get out of this," Will stated, "I'm going to make it my business to find out whether that detective is regularly employed on this case. He looks to me like a crook!"
It was dreary waiting there in the sealed-up chamber, and the boys found themselves dropping into long intervals of silence while they listened for the gurgle of the water which would indicate that the great pumps had been set in motion.
During one of those intervals of silence, they heard sounds which brought them to their feet in great excitement. Almost unable to believe his ears, Will turned to George with a question on his lips:
"Did you hear that?" he asked.
"Of course I did!"
"I did, too, but I thought I must be dreaming."
"No dream about that!" replied George. "That's the call of the Beaver Patrol!"
"And that means that Tommy and Sandy are not far away!"
"We heard the call of the Wolf Patrol not long ago," suggested George. "I wonder if this blooming old mine is chock full of Boy Scouts of assorted sizes. There can't be too many here to please me!"