Like a great dragonfly dipping over a still pond, he darted toward his prey. At the moment the shrapnel bullets were thickest about his machine, he touched the switch that released the eight rockets.

A sheet of flame hid his machine for a moment, and a spray of sparks spread out, following the flight of the incendiary missiles. The darts were well aimed; probably all of them found their billets in the huge bag of the balloon.

The "saucisse" sagged. Flames crept slowly around the silken envelope. The little Nieuport darted away while the observation balloon burst and fell to the ground with its unfortunate human burden, a mass of flames.

Within an hour seven great balloons were thus destroyed by the French aviators, and then the others were withdrawn from service for the day. The Germans marched on across the fields that had heretofore rung to the tread of French-shod feet; but their line of observation was broken.

Frank Sanderson returned from the successful raid for some small repairs and to have his mitrailleuse again affixed upon the nose of the aeroplane. There was much freedom allowed in the camp of the Lafayette Escadrille, or else the visitor Frank found waiting for him had a deal of influence with the military authorities.

"Captain Dexter!" Sanderson exclaimed, seeing trouble in the Yankee shipmaster's face the moment he removed his cap and mask, "what is the matter?"

"Belinda!" ejaculated the captain. "Have you seen the girl? Where is she?"

"Isn't she with the hospital unit?"

"No. I've been there. Moved heaven and earth to get a permit to come up here the moment we heard the hospital station was changed. Her aunt insisted. And Belinda isn't there!"

"You—you——Are you sure?" stammered Sanderson.