“The story is all right, Mr. Carson,” explained Tim? “but if you print it tomorrow the gang responsible for the robbery of the air mail will never be captured. If you’ll hold the story for twenty-four hours there’s a good chance that they can be apprehended.”

“Not much,” snorted the managing editor, “at least not as long as they have the death ray machine.”

“You’re wrong there,” persisted Tim. “It’s not only possible that they can be captured, but if you’ll give me permission to use the News’ plane I think I can turn the trick.”

Carson was too surprised for words and before the managing editor could regain his poise Tim continued, driving his argument home. For over an hour they talked in low, strained voices, with Carson openly protesting at times as Tim explained his plan. Finally the managing editor gave his consent and Tim arose to go.

“Good luck, Tim,” said Carson, “I’ll see the air mail people the first thing in the morning and fix everything up for you.”

Dead tired, Tim went to his room and turned in, but sleep would not come. Through the rest of the night his mind pictured the lurking bandit plane, the helpless mail flyer, the death ray fired from the gun, and then the bandit drifting earthward to feast on the spoils of the wreckage. Tim turned and tossed, enraged that men should stoop to such villainy, that an achievement of science should be turned to such low ends.

All next day Tim and a crew of mechanics at the municipal field worked desperately on the Lark in a secluded hangar. Carefully they sheathed the motor cowling and the fuselage with thin layers of lead and zinc, alternately spreading them on for they were as thin as paper. By nightfall the crimson plane was half gray with the cockpit and its vital parts protected by the thin sheathing of metal.

The Lark was ready for the test and the chances were that it would come that night. The two previous nights had been clear as crystal with a full moon riding the sky. The pilots of the mysterious vulture of the air would not be abroad on such nights for the risk of detection would be too great. Now, however, a thin cloud film at high altitude had spread over the heavens, making an ideal night for another raid on the air mail. And there was no doubt in Tim’s mind but that they would raid again. They had not the slightest reason to believe that their secret had been discovered and certainly the valuables carried nightly by the mail plane would lure them into further attacks.

Well, Tim was ready for them, but the thought of actually doing battle in the air gave him many a nervous chill as he waited that evening for the time to go into action.

A figure hurried across the field and toward the hangar.