his upturned face, even as the cool mountain air smote his fevered brow, the dark earth erupted beneath his feet, a whirlwind of smoke and wind beat and buffeted him, and, in the midst of an overwhelming noise, consciousness was blotted out!

It was bright daylight when Talbot regained his senses. Propped against a great rock the Professor regarded him whimsically. Reubens looked badly bruised and battered; one arm hung loosely at his side. Talbot's head ached and he knew that a leg was broken.

"Yes," said the Professor, "we got through just in time—a few seconds before the explosive gas was touched off. Thank God, my invention has been destroyed. The world is safe."

Yes, the world was safe. Talbot sank back with a sigh of relief. Overhead a white plane was dipping toward earth.