The secret of the old mill

by Franklin W. Dixon

But while the Sleuth was still some distance away from the mouth of the river, her speed began to slacken.

"Good!" exclaimed Joe. "The gas tank's empty."

"Let us hope so," returned his brother. "What a sell for that man!"

But a moment later the other motorboat began to show signs of life again.

"She's started up!" groaned Joe. "Confound the luck, anyway."

A moment later a splutter came from the other boat.

"Gas must be running low," said Frank. "Gee, I wish he would stop entirely!"

"Same here."

Slower and slower went the white motorboat until at last it was just crawling along.

Frank picked up the binoculars again.