“It’s queer,” he murmured idly, “you’d think the stitches would have rotted. They look just as good as new.”

They cut them carefully and ripped away the oilskin. Inside was a small folded sheet of paper. With trembling fingers they unfolded it. The sheet was blank! They stared at each other, puzzled.

“A dummy?” hazarded Julius. “Was Danvers just a decoy?”

Tommy shook his head. That solution did not satisfy him. Suddenly his face cleared.

“I’ve got it! Sympathetic ink! ”

“You think so?”

“Worth trying anyhow. Heat usually does the trick. Get some sticks. We’ll make a fire.”