The strong air current which spread horizontally over the thunderhead blew Dorothy’s plane sideways and away from the cloud. An instant later it was roaring downward in the thin air, quite beyond her control, a self-propelled projectile rushing to its doom.

While shooting upward in the cloud, the violent and intensely rapid gyrations of the airship caused her safety belt to become unclasped, and had her parachute not caught in the cowling, she must have been flung clear of the plane to a horrible death far below.

With her heels still hooked beneath the pilot’s seat, she wrenched the parachute loose. Then she closed the throttle and half-suffocated by the force of the wind and lack of breathable oxygen, she commenced to pull the stick slowly backward.

A glance at the altimeter showed a height of eighteen thousand feet—three air miles above earth—and three thousand feet above Will-o’-the-Wisp’s service ceiling.

Notwithstanding the shut-off engine, the speed of the diving plane was terrific. Dorothy felt the grinding jar of the wind-strained wings as the nose began to rise in answer to the pull of the elevators; and wondered helplessly if they would hold.

The air pressure was agony to her eardrums. Her head reeled. She was well-nigh exhausted. She no longer cared very much what happened.

The plane dropped into a blanket of fog. She felt the wet mist on her face, refreshing and reanimating her. Suddenly she realized that her parachute was starting to fill and would shortly pull her out of the cockpit. With her free hand she reached under the seat and brought forth a sheath knife. A frenzied second later she had rid herself of the flapping bag. As it flew overboard, she tightened her safety belt and placed her cramped feet back on the steering pedals.

Though still fog-blind, she could at least breathe comfortably now as the plane lessened speed in descent. Will-o’-the-Wisp still shook and groaned, but no longer fought the pull of the stick. Up came the nose, slowly but surely and with her ailerons functioning once more, Dorothy gained control and sent the plane into a normal glide. The altimeter marked five thousand feet. The dive had been over two miles long.

Another fifteen hundred feet and gradually the mist lightened until it became mere wisps of smoky cloud. Long Island Sound had been left behind. Below lay the wooded hills and valleys of the Connecticut ridge country, cloaked in multi-shaded green. As she still headed north, Dorothy knew now that she had been blown beyond New Canaan. She gave the plane hard right rudder and right aileron and sent it swinging into a long half spiral, which, completed, headed her south again. Almost directly below, she recognized the Danbury Fair Grounds, with home just twenty miles away.

Again her hand sought the throttle and as Will-o’-the-Wisp snorted, then roared, Dorothy breathed a thankful sigh. Fifteen minutes later she had housed her plane in its hangar, and was limping up the porch steps of her home.

Lizzie, the Dixons’ servant, met her in the hall.

“Whatever is the matter, Miss Dorothy? You’ve had an accident—you’re half-killed—I know you are! There’s blood all over your face—”

Her young mistress interrupted, smiling:

“You’re wrong again, Lizzie. No accident, though I know I look pretty awful. I feel that way, too, if you ask me—”

“But the blood, Miss Dorothy?”

“It’s from a nosebleed, Lizzie. I assure you I’m not badly hurt. If you’ll help me out of these rags and start a warm bath running, I’ll be ever so much obliged. A good soaking in hot water will fix me up. Then,” she added, “I think I’ll be real luxurious and have my dinner in bed.”

When the solicitous Lizzie brought up the dinner tray three-quarters of an hour later, a tired but decidedly sprucer Dorothy, in pink silk pyjamas, was leaning back against her pillows.

“My word, I’m hungry!” She seized a hot roll and began to butter it. “I’m off bucking thunderheads for life, Lizzie. But you can take it from me, that kind of thing gives you a marvelous appetite!”

“Yes, miss, I’m glad,” returned Lizzie, who had no idea what Dorothy was talking about. “You certainly look better.”

“By the way, what’s become of Daddy? Hasn’t he got home yet?”

“Oh, Miss Dorothy, I’m so sorry. Sure and I forgot to tell ye—Mr. Dixon won’t be home for dinner.”

“Did he telephone?”

“No, miss. He came home about quarter to five and packed his suitcase. He said to tell you he’d been called to Washington on business and he’d be gone a couple of days. Arthur drove him to Stamford to catch the New York express—he didn’t have much time.”

Dorothy helped herself to a spoonful of jellied bouillon. “Any other message?”

“Yes, miss. He said that Mister Terry hadn’t been found yet. I asked him b’cause I thought you’d like to know. That was all he said. I’m sure sorry I forgot it when you came in, but I—”

“That’s all right, Lizzie, I understand. You come back for the tray in half an hour, will you? And if you find me asleep, don’t wake me up. I’m tired to death. I need a long rest and I’m going to take it.”

When Lizzie came back she found Dorothy deep in the sleep of exhaustion. She lowered the window blinds against the early morning light and picking up the tray from the end of the bed, tiptoed from the room.

Morning broke bright and clear with no sign of yesterday’s mist and rain. Dorothy remained in bed for breakfast and it took but little persuasion on the part of Lizzie to keep her there till lunch time. She still felt stiff and bruised and was only too content to rest and doze.

Toward noon she rose and dressed in her flying clothes. Immediately after lunch she went out to the hangar. She slipped into a serviceable and grubby pair of overalls, and spent the afternoon in giving Will-o’-the-Wisp a thorough grooming. At quarter to five she was in the air and headed for Long Island Sound.

Half an hour later, with an altitude of ten thousand feet, she was cruising over yesterday’s course above the Long Island shore, when she spied a biplane coming across the Sound. In an instant she had her field glasses out and focussed on the newcomer.

“That’s him!” she murmured ungrammatically, though with evident relief. “Now for a pleasant little game of hide-and-seek!”

The Mystery Plane was flying far below, so continuing on her course at right angles, she watched it with hurried glances over her shoulder. When she reached the Long Island Shore line, it was a mile or so behind and below Dorothy’s tailplane. So waiting only long enough to be sure that her quarry was headed across the Island, she banked her plane and sent it on a wide half circle to the right. Long Island, at this point, she knew was about twenty miles wide.

Dorothy’s plan for trailing the Mystery Plane and doing so without being seen, was as simple as it was direct. The farther end of her circular course would bring her over Great South Bay and the South shore of Long Island at approximately the same point for which the other plane seemed to be bound. She would arrive, of course, a minute or two behind the other aviator. And as she planned, so it happened.

From her high point of vantage, Dorothy, swinging on her arc a mile or so to the east, was able to keep the other amphibian continually in sight. She watched him pursue his southerly course until he came over the town of Babylon on Great South Bay. Here her glasses told her that the bearded aviator turned his plane to the left, heading east and up the bay in her direction.

Below her now lay the Bay, hemmed in from the Atlantic by long narrow stretches of white sand dunes. For a second or so Dorothy thought they would pass in the air, her plane far above the other. But before she reached that point, she saw the other make a crosswind landing and taxi toward a dock which jutted into the Bay from the dunes. Just beyond the dock an isolated cottage stood in a hollow on the bay side of the dunes. There was no other habitation in sight for over a mile in either direction.

“Aha! Run to earth at last!” muttered Dorothy contentedly. Maintaining her altitude, with Babylon across the bay to her right, she continued her westward course above the dunes.

A few miles past the cottage she flew over Fire Island Inlet. When she was opposite Amityville, she came about. Shutting off her engine, she tilted the stick forward and sent Will-o’-the-Wisp into a long glide which eventually landed her on the waters of Babylon harbor.

Dorothy stripped off her goggles and scanned the waterfront. Slightly to her left she spied a small shipyard, whose long dock bore a large sign which carried the legend: “Yancy’s Motor Boat Garage.”

“Good. Couldn’t be better!” exclaimed Miss Dixon in great satisfaction. “Atta girl, Wispy! We’re going over to have a talk with Mr. Yancy.”

She gave her plane the gun and taxiing slowly over the smooth water, through the harbor shipping, presently brought up at the Yancy wharf and made fast.

“Hello, there! Want gas?” sang out a voice above her, and Dorothy looked up. A smiling young man, dressed in extremely dirty dungarees was walking down the wharf toward her.

“Hello, yourself!” she returned as he came up. “No, I’m not out of gas, thank you. I want to hire a boat.”

“Better come ashore, then.” The man wiped his palms on a piece of clean cotton waste and gave her a hand up. “We’ve got plenty of boats—all kinds, lady. Got ’em fast and slow, big and little. Just what kind of a craft do you need?”

“Something with plenty of beam and seaworthy, that I can run without help. I’m not looking for speed. I may want to take her outside—I don’t know.”

The young man pointed down the wharf to where a rather bulky motor boat, broad of beam and about thirty feet waterline was moored head out to a staging.

“Mary Jane—that’s your boat,” announced Mr. Yancy. “She’s old and she ain’t got no looks, but she’s seaworthy and she’ll take you anywhere. You could run over to Paris or London in that old craft if you could pile enough gas aboard her.”

“She looks pretty big,” Dorothy’s tone was dubious. “Think I can handle her by myself?”

“She is big,” he admitted readily, “but she runs like a sewing machine and she’s all set to be taken out this minute if you want her.”

“I’ll look her over anyway,” she declared and led the way to the landing stage.

Stepping aboard the Mary Jane, she peeped into the small trunk cabin which was scarcely bigger than a locker, but would give shelter in case of rain. She observed that there were sailing lights, compass, horn and a large dinner bell in a rack, and two life preservers as well. In one of the lockers she came upon a chart. Stowed up in the forepeak were an anchor with a coil of line and three five-gallon tins of gasoline. A quick examination showed the fuel tank to have been filled.

The motor was a simple and powerful two-cylinder affair, with make-and-break ignition, noisy, but dependable; the sort of engine on which the fishermen and lobstermen along the coast hang their lives in offshore work. It seemed to Dorothy that it ought to kick the shallow old tub along at a good ten-knot gait. The boat itself though battered and dingy, appeared to be sound and staunch so far as one could see.

“I’ll take her,” decided Dorothy. “That is, if she’s not too expensive?”

“I guess we ain’t goin’ to fight about the price, mam,” asserted Yancy. “How long will you be wantin’ her and when do you expect to take her out?”

“Not before nine tonight—and I’ll hire her for twenty-four hours.”

“O. K. mam. You can have her for a year if you want her. How about your air bus?”

“She’ll be left here. I want you to look after her. I don’t think there’ll be any wind to speak of. She’ll be all right where she is.”

“We’re going to get rain in a couple of hours, so if you’ll make her secure, I’ll have her towed out to that buoy yonder. I’ll rest easier with her moored clear of this dock.”

“I’ll pull the waterproof covers over the cockpits and she’ll be all right,” returned Dorothy. “Then we can go up to your office and fix up the finances.”