Garrison walked along the road to Hickwood out of sheer love of being in the open, and also the better to think.

Unfortunately for the case in hand, however, his thoughts wandered truantly back to New York and the mystery about the girl masquerading to the world as his wife. His meditations were decidedly mixed. He thought of Dorothy always with a thrill of strong emotions, despite the half-formed suspicions which had crossed his mind at least a dozen times.

Her jewels were still in his pocket—a burden she had apparently found too heavy to carry. How he wished he might accept her confidence in him freely, unreservedly—with the thrill it could bring to his heart!

The distance to Hickwood seemed to slip away beneath his feet. He arrived in the hamlet far too soon, for the day had charmed bright dreams into being, and business seemed wholly out of place.

The railroad station, a store, an apothecary's shop, and a cobbler's little den seemed to comprise the entire commercial street.

Garrison inquired his way to the home of his man—the inventor.

Scott, whom he found at a workshop, back of his home, was a thin, stooped figure, gray as a wolf, wrinkled as a prune, and stained about the mouth by tobacco. His eyes, beneath their overhanging brows of gray, were singularly sharp and brilliant. Garrison made up his mind that the blaze in their depths was none other than the light of fanaticism.

"How do you do, Mr. Scott?" said the detective, who had determined to pose as an upper-air enthusiast. "I was stopping in Branchville for a day or two, and heard of your fame as a fellow inventor. I've been interested in aeroplanes and dirigible balloons so long that I thought I'd give myself the pleasure of a call."

"Um!" said Scott, closing the door of his shop behind him, as if to guard a precious secret. "What did you say is your name?"

Garrison informed him duly.

"I haven't yet made myself famous as a navigator of the air, but we all have our hopes."

"You'll never be able to steer a balloon," said Scott, with a touch of asperity. "I can tell you that."

"I begin to believe you're right," assented Garrison artfully. "It's a mighty discouraging and expensive business, any way you try it."

"I'll do the trick! I've got it all worked out," said Scott, betrayed into ardor and assurance by a nearness of the triumph that he felt to be approaching. "I'll have plenty of money to complete it soon—plenty—plenty—but it's a long time coming, even now."

"That's the trouble with most of us," Garrison observed, to draw his man. "The lack of money."

"Why can't they pay it, now the man is dead?" demanded Scott, as if he felt that everyone knew his affairs by heart and could understand his meaning. "I need the money now—to-day—this minute! It's bad enough when a man stays healthy so long, and looks as if he'd last for twenty years. That's bad enough without me having to wait and wait and wait, now that he's dead and in the ground."

It was clear to Garrison the man's singleness of purpose had left his mind impaired. He began to see how a creature so bent on some wondrous solution of the flying-machine enigma could even become so obsessed in his mind that to murder for money, insurance benefits, or anything else, would seem a fair means to an end.

"Some friend of yours has recently died?" he asked. "You've been left some needed funds for your labors?"

"Funny kind of friendship when a man goes on living so long," said the alert fanatic. "And I don't get the money; that's what's delaying me now."

"You're far more fortunate than some of us," said Garrison. "Some friend, I suppose, here in town."

"No, he was here two days," answered Scott. "I saw him but little. He died in the night, up to the village." His sharp eyes swung on Garrison peculiarly the moment his speech was concluded.

He demanded sharply; "What's all this business to you?"

"Nothing—only that it shows the world's great inventors are not always neglected, after all," answered Garrison. "Some of us never enjoy such good fortune."

"The world don't know how great I am," declared the inventor, instantly off, on the hint supplied by his visitor. "But just the minute that insurance company gives me the money, I'll be ready to startle the skies! I'll blot out the stars for 'em! I'll show New York! I know what I'm doing! And nothing on earth is going to stop me! All these fool balloonists, with their big silk floating cigars! Deadly cigars is what they are—deadly! You wait!"

Garrison was staring at him fixedly, fascinated by a new idea which had crept upon his mind with startling abruptness. His one idea was to get away for a vital two minutes by himself.

"Well, perhaps I'll try to get around again," he said. "I can see you're very busy, and I mustn't keep you longer from your work. Good luck and good-day."

"The only principle," the old man answered, his gaze directed to the sky.

Garrison looked up, beholding a bird, far off in the azure vault, soaring in the majesty of flight. Then he hastened again to the quiet little street, and down by a fence at a vacant lot, where he paused and looked about. He was quite alone. Drawing from his pocket the envelope containing the old cigar that Hardy had undoubtedly let fall as he died at the porch of the "haunted" house, he turned up the raggedly bitten end.

"By George!" he exclaimed beneath his breath.

Tucked within the tobacco folds, in a small hollow space which was partially closed by the filler which had once been bitten together, was a powdery stuff that seemed comprised of small, hard particles, as of crystals, roughly broken up.

His breath came fast. His heart was pumping rapidly. He raised the cigar to his nostrils and smelled, but could only detect the pungent odor of tobacco.

That the powder was a poison he had not the slightest doubt. Aware that one poison only, thus administered, would have the potency to slay an adult human being practically on the instant, he realized at once that here, at the little, unimportant drug-shop of the place, the simple test for such a stuff could be made in a matter of two minutes.

Eager and feverish to inform himself without delay, he took out his knife and carefully removed all the powder from its place and wrapped it most cautiously about in the paper of the envelope in hand. The cigar he returned to his pocket.

Five minutes later, at the drug-store down the street, an obliging and clever young chemist at the place was holding up a test-tube made of glass, with perhaps two thimblefuls of acidulated solution which had first been formed by dissolving the powder under inspection.

"If this is what you suppose," he said, "a slight admixture of this iron will turn it Prussian blue."

He poured in the iron, which was likewise in solution, and instantly the azure tint was created in all its deadly beauty.

Garrison was watching excitedly.

"No mistake about it," said the chemist triumphantly. "Where did you find this poison?"

"Why—in a scrap of meat," said Garrison, inventing an answer with ready ingenuity; "enough to have killed my dog in half a shake!"