"I believe we'll do well to watch Bradley," he suggested.
"But Bradley was at the cabin when we got there."
"Oh, he had plenty of time to get Jimmie away and get back to the cabin!" Frank insisted. "We remained at the cave half an hour after Jimmie left us, and we took our time in getting to the cottage."
"Also we took a great many snap-shots at the scenery," Ned went on. "Now, I wish you would take all the films out of the cameras and develop and print a picture of each."
"I'll go right at it," Frank replied, turning back to the tent.
"And if any of the boys were taking pictures about the tent, or the corral, have them developed. It may be that one of the snap-shots will show the person who slipped the note into the tent."
"I don't see how it was ever done without the man being seen," Frank exclaimed.
"But it was done," Ned replied, "and we've got to find out when and how if we can."
When Frank left for the tent Ned started on toward the summit. He had traveled only a short distance when Frank came puffing after him.
"Here's another print Jack and Teddy took," he said. "It shows something in the cave we never noticed. See if you can tell what it is."