It was the regular Saturday night dance at the club, a brilliant
spectacle, faces that radiated pleasure, gowns that for startling
combinations of color would have shamed a Futurist, music that set
the feet tapping irresistibly--a scene which I shall pass over
because it really has no part in the story.
The fascination of the ballroom was utterly lost on Craig. "Think
of all the houses only half guarded about here to-night," he
mused, as we joined Armand and McNeill on the end of the dock. I
could not help noting that that was the only idea which the gay,
variegated, sparkling tango throng conveyed to him.
In front of the club was strung out a long line of cars, and at
the dock several speed boats of national and international
reputation, among them the famous Streamline II, at our instant
beck and call. In it Craig had already placed some rather bulky
pieces of apparatus, as well as a brass case containing a second
triple mirror like that which he had left with Armand.
With McNeill, I walked back along the pier, leaving Kennedy with
Armand, until we came to the wide porch, where we joined the
wallflowers and the rocking-chair fleet. Mrs. Verplanck, I
observed, was a beautiful dancer. I picked her out in the throng
immediately, dancing with Carter.
McNeill tugged at my sleeve. Without a word I saw what he meant me
to see. Verplanck and Mrs. Hollingsworth were dancing together.
Just then, across the porch I caught sight of Kennedy at one of
the wide windows. He was trying to attract Verplanck's attention,
and as he did so I worked my way through the throng of chatting
couples leaving the floor until I reached him. Verplanck,
oblivious, finished the dance; then, seeming to recollect that he
had something to attend to, caught sight of us, and ran off during
the intermission from the gay crowd to which he resigned Mrs.
Hollingsworth.
"What is it--that light again?" she asked, as she joined us in
walking down the dock.
"Yes," answered her husband, pausing to look for a moment at the
stuff Kennedy had left with Armand. Mrs. Verplanck leaned over the
Streamline, turned as she saw me, and said: "I wish I could go
with you. But evening dress is not the thing for a shivery night
in a speed boat. I think I know as much about it as Mr. Verplanck.
Are you going to leave Armand?"
"Yes," replied Kennedy, taking his place beside Verplanck, who was
seated at the steering wheel. "Walter and McNeill, if you two will
sit back there, we're ready. All right."
Armand had cast us off and Mrs. Verplanck waved from the end of
the float as the Streamline quickly shot out into the night, a
buzzing, throbbing shape of mahogany and brass, with her exhausts
sticking out like funnels and booming like a pipe organ. It took
her only seconds to eat into the miles.
"A little more to port," said Kennedy, as Verplanck swung her
around.
Just then the steady droning of the engine seemed a bit less
rhythmical. Verplanck throttled her down, but it had no effect. He
shut her off. Something was wrong. As he crawled out into the
space forward of us where the engine was, it seemed as if the
Streamline had broken down suddenly and completely.
Here we were floundering around in the middle of the bay.
"Chuck-chuck-chuck," came in quick staccato out of the night. It
was Montgomery Carter, alone, on his way across the bay from the
club, in his own boat.
"Don't know. Engine trouble of some kind. Can you give us a line?"
"I've got to go down to the house," he said, ranging up near us.
"Then I can take you back. Perhaps I'd better get you out of the
way of any other boats first. You don't mind going over and then
back?"
Verplanck looked at Craig. "On the contrary," muttered Craig, as
he made fast the welcome line.
The Carter dock was some three miles from the club on the other
side of the bay. As we came up to it, Carter shut off his engine,
bent over it a moment, made fast, and left us with a hurried,
"Wait here."
Suddenly, overhead, we heard a peculiar whirring noise that seemed
to vibrate through the air. Something huge, black, monster-like,
slid down a board runway into the water, traveled a few feet, in
white suds and spray, rose in the darkness--and was gone!
As the thing disappeared, I thought I could hear a mocking laugh
flung back at us.
"What is it?" I asked, straining my eyes at what had seemed for an
instant like a great flying fish with finny tail and huge fins at
the sides and above.
"'Aquaero,'" quoted Kennedy quickly. "Don't you understand--a
hydroaeroplane--a flying boat. There are hundreds of privately
owned flying boats now wherever there is navigable water. That was
the secret of Carter's boathouse, of the light we saw in the air."
"But this Aquaero--who is he?" persisted McNeill. "Carter--
Wickham--Australia Mac?"
We looked at each other blankly. No one said a word. We were
captured, just as effectively as if we were ironed in a dungeon.
There were the black water, the distant lights, which at any other
time I should have said would have been beautiful.
"The deuce," he exclaimed. "He's put her out of business."
Verplanck, chagrined, had been going over his own engine
feverishly. "Do you see that?" he asked suddenly, holding up in
the light of a lantern a little nut which he had picked out of the
complicated machinery. "It never belonged to this engine. Some one
placed it there, knowing it would work its way into a vital part
with the vibration."
Who was the person, the only one who could have done it? The
answer was on my lips, but I repressed it. Mrs. Verplanck herself
had been bending over the engine when last I saw her. All at once
it flashed over me that she knew more about the phantom bandit
than she had admitted. Yet what possible object could she have had
in putting the Streamline out of commission?
My mind was working rapidly, piecing together the fragmentary
facts. The remark of Kennedy, long before, instantly assumed new
significance. What were the possibilities of blackmail in the
right sort of evidence? The yeggman had been after what was more
valuable than jewels--letters! Whose? Suddenly I saw the
situation. Carter had not been robbed at all. He was in league
with the robber. That much was a blind to divert suspicion. He was
a lawyer--some one's lawyer. I recalled the message about letters
and evidence, and as I did so there came to mind a picture of
Carter and the woman he had been dancing with. In return for his
inside information about the jewels of the wealthy homes of
Bluffwood, the yeggman was to get something of interest and
importance to his client.
The situation called for instant action. Yet what could we do,
marooned on the other side of the bay?
From the Club dock a long finger of light swept out into the
night, plainly enough near the dock, but diffused and disclosing
nothing in the distance. Armand had trained it down the bay in the
direction we had taken, but by the time the beam reached us it was
so weak that it was lost.
Craig had leaped up on the Carter dock and was capping and
uncapping with the brass cover the package which contained the
triple mirror.
Still in the distance I could see the wide path of light, aimed
toward us, but of no avail.
"Using the triple mirror to signal to Armand. It is something
better than wireless. Wireless requires heavy and complicated
apparatus. This is portable, heatless, almost weightless, a source
of light depending for its power on another source of light at a
great distance."
I wondered how Armand could ever detect its feeble ray.
"Even in the case of a rolling ship," Kennedy continued,
alternately covering and uncovering the mirror, "the beam of light
which this mirror reflects always goes back, unerring, to its
source. It would do so from an aeroplane, so high in the air that
it could not be located. The returning beam is invisible to anyone
not immediately in the path of the ray, and the ray always goes to
the observer. It is simply a matter of pure mathematics
practically applied. The angle of incidence equals the angle of
reflection. There is not a variation of a foot in two miles."
"What message are you sending him?" asked Verplanck.
"To tell Mrs. Hollingsworth to hurry home immediately," Kennedy
replied, still flashing the letters according to his code.
"Yes. This hydroaeroplane yeggman is after something besides
jewels to-night. Were those letters that were stolen from you the
only ones you had in the safe?"
Verplanck looked up quickly. "Yes, yes. Of course."
"No," he almost shouted. Of a sudden it seemed to dawn on him what
Kennedy was driving at--the robbery of his own house with no loss
except of a packet of letters on business, followed by the attempt
on Mrs. Hollingsworth. "Do you think I'd keep dynamite, even in
the safe?"
To hide his confusion he had turned and was bending again over the
engine.
"Able to run on four cylinders and one propeller," replied
Verplanck.
"Then let's try her. Watch the engine. I'll take the wheel."
Limping along, the engine skipping and missing, the once peerless
Streamline started back across the bay. Instead of heading toward
the club, Kennedy pointed her bow somewhere between that and
Verplanck's.
"I wish Armand would get busy," he remarked, after glancing now
and then in the direction of the club. "What can be the matter?"
"A German invention for use at night against torpedo and aeroplane
attacks. From that mortar Armand has shot half a dozen bombs of
phosphide of calcium which are hurled far into the darkness. They
are so constructed that they float after a short plunge and are
ignited on contact by the action of the salt water itself."
It was a beautiful pyrotechnic display, lighting up the shore and
hills of the bay as if by an unearthly flare.
In the glow we could see a peculiar, birdlike figure flying
through the air over toward the Hollingsworth house. It was the
hydroaeroplane.
Out from the little stretch of lawn under the accentuated shadow
of the trees, she streaked into the air, swaying from side to side
as the pilot operated the stabilizers on the ends of the planes to
counteract the puffs of wind off the land.
The Streamline, halting and limping, though she was, had almost
crossed the bay before the light bombs had been fired by Armand.
Every moment brought the flying boat nearer.
She swerved. Evidently the pilot had seen us at last and realized
who we were. I was so engrossed watching the thing that I had not
noticed that Kennedy had given the wheel to Verplanck and was
standing in the bow, endeavoring to sight what looked like a huge
gun.
In rapid succession half a dozen shots rang out. I fancied I could
almost hear the ripping and tearing of the tough rubber-coated
silken wings of the hydroaeroplane as the wind widened the
perforation the gun had made.
She had not been flying high, but now she swooped down almost like
a gull, seeking to rest on the water. We were headed toward her
now, and as the flying boat sank I saw one of the passengers rise
in his seat, swing his arm, and far out something splashed in the
bay.
On the water, with wings helpless, the flying boat was no match
for the Streamline now. She struck at an acute angle, rebounded in
the air for a moment, and with a hiss skittered along over the
waves, planing with the help of her exhaust under the step of the
boat.
There she was, a hull, narrow, scow-bowed, like a hydroplane, with
a long pointed stern and a cockpit for two men, near the bow.
There were two wide, winglike planes, on a light latticework of
wood covered with silk, trussed and wired like a kite frame, the
upper plane about five feet above the lower, which was level with
the boat deck. We could see the eight-cylindered engine which
drove a two-bladed wooden propeller, and over the stern were the
air rudder and the horizontal planes. There she was, the hobbled
steed now of the phantom bandit who had accomplished the seemingly
impossible.
In spite of everything, however, the flying boat reached the shore
a trifle ahead of us. As she did so both figures in her jumped,
and one disappeared quickly up the bank, leaving the other alone.
"Verplanck, McNeill--get him," cried Kennedy, as our own boat
grated on the beach. "Come, Walter, we'll take the other one."
The man had seen that there was no safety in flight. Down the
shore he stood, without a hat, his hair blown pompadour by the
wind.
As we approached Carter turned superciliously, unbuttoning his
bulky khaki life preserver jacket.
"It was you who suggested the millionaire households, full of
jewels, silver and gold, only half guarded; you, who knew the
habits of the people; you, who traded that information in return
for another piece of thievery by your partner, Australia Mac--
Wickham he called himself here in Bluffwood. It was you---"
A car drove up hastily, and I noted that we were still on the
Hollingsworth estate. Mrs. Hollingsworth had seen us and had
driven over toward us.
"Yes," said Kennedy quickly, "air pirate and lawyer for Mrs.
Verplanck in the suit which she contemplated bringing--"
Mrs. Hollingsworth grew pale under the ghastly, flickering light
from the bay.
"Oh!" she cried, realizing at what Kennedy hinted, "the letters!"
"At the bottom of the harbor, now," said Kennedy. "Mr. Verplanck
tells me he has destroyed his. The past is blotted out as far as
that is concerned. The future is--for you three to determine. For
the present I've caught a yeggman and a blackmailer."