“Don’t you worry,” Jack assured him. “Nothing is going to get away with any monkey shines to-night.”

Two o’clock came and they had heard no sound to alarm them. It was almost three when a slight sound down close to the shore attracted Jack’s attention.

“Did you hear it?” he asked, trying to pierce the darkness.

“Yep. Let’s make a rush for it.”

“Come on.”

Together they ran for the lake, some twenty feet distant.

“There it goes,” Rex cried.

“After it,” Jack echoed.

But, although they ran as fast as they dared in the darkness, the thing had disappeared in the thick woods before they could reach it.

“Mebby it’s just as well at that,” Rex said as they paused at the edge of the forest.