"No," replied A--, rather ruefully, I fancied. "He said the machinery
was so perfect that it would practically run itself from our electric
accumulators, and that he would give us an absolutely free hand with
it."
"I wonder how many of you would have come back?" I said meaningly.
A--swore fervently, and I saw by the gleam in his eyes that he was fully
awake to the possibilities of the trap into which he had been so nearly
led.
Our task now, barring some unforeseeable contingency, was fairly easy;
there was a good prospect of ensnaring our foes in the pit they had so
skilfully dug for us.
"The matter is up to you now," I told A--. "I'm going to drop out till
the very last minute. But I shall be with you then. It is of the
utmost importance that we shall do nothing to scare these very wary
birds. What is your plan?"
"Well," said A--, "it seems to me I had better go ahead as if nothing
had happened. The arrangement is that Engstrom shall take his apparatus
to Havre and instal it on E77. We are then to put to sea for the tests,
and are to meet him later and inform him of our decision."
"That will do all right," I said. "I shall come on board the submarine
before Engstrom arrives, and then I think we shall surprise him."
A--departed at once to make the final arrangements and I busied myself
in sending off some telegrams arranging for the final downfall of the
Hun plotters.
A week later I found myself on board E77 at Havre. The mysterious cases
had been sent on, and with them came Engstrom, with Thornton and
Tegelmund, who professed to be interested in the venture--the former
financially, the latter as the inventor. Tegelmund was in high glee at
being thus afforded an opportunity of putting his device to a thoroughly
satisfactory test. We also had a big surprise in the arrival of
Halbmayr, who arrived in Havre under the name of Mennier. That he
should have ventured on the scene at all showed how intensely interested
he was.
Engstrom declared that the fitting of the machinery would occupy fully
three days, and we, of course, humoured him in every way possible. A--
made himself particularly agreeable, playing the part of host to
perfection, and it was evident that the conspirators never even dreamed
that their nefarious designs were suspected by the genial naval officer
who showed such an enthusiastic interest in the wonderful stories with
which they plied him on the merits of their great discovery.
The three days went by. Four great cases of machinery had been duly
shipped on board, and Engstrom, Thornton, and Tegelmund spent many hours
daily at their work in the interior of the submarine. Of course I could
not appear--I should have been recognised at once--but among the crew of
the submarine were a couple of the smartest men of the Surete, who kept
the bogus engineer and his associates under the closest scrutiny. They
reported to me that Engstrom appeared to be the only one of the three
with any great amount of mechanical knowledge, and that, while Tegelmund
worked assiduously at his machine, the others spent most of their time
carefully examining the details of the British vessel, in which they
showed the greatest interest. I began to get at last an inkling of the
plot!
The fourth day dawned--the day of the _denouement_. Early in the
morning I slipped on board the submarine, and when the two conspirators
arrived we made our coup.
Engstrom, when he came on board with Tegelmund, found himself suddenly
confronted by the Commander, with a stalwart bluejacket standing on
either side of him. He was curtly informed that he could not go below.
"But you promised!" he shrieked, livid with vexation.
"True!" said the Commander. "But you call yourself Oscar Engstrom, of
Malmo, and I happen to have the real Mr Engstrom here."
The engineer went white to the very lips as Mr Engstrom, who had come
post-haste from Stockholm in response to my urgent cable, emerged from
behind the conning-tower, closely followed by myself. The false
Engstrom began a vehement protest, but ceased suddenly, for, glancing
round, he saw Tegelmund also under guard. The game was up!
A few minutes later, with Engstrom and Tegelmund safely in irons, the
Admiralty experts who had come over from London began a minute
examination of the wonderful "invention." They soon discovered that the
cases contained a jumble of wires and odds and ends of mechanical scraps
simply thrown together to look complicated, and of no value whatever for
the renewal of vitiated air.
The real object was only revealed when we had got to the very heart of
the amazing collection of rubbish. There, cunningly hidden among much
that was superfluous, was a highly efficient electric motor, wonderfully
made and controlling a powerful bomb by machinery, set to detonate the
explosive after six hours' running. The machinery was to have been
operated by the electric batteries of the submarine, and had the E77
gone to sea and begun the "tests" of the bogus apparatus, not a vestige
of the vessel or the crew would have been seen again, and the secret of
her loss would have been locked for ever in the depths of the Atlantic.
But this, we found, was only a part of the plot--perhaps even the least
important part. Tegelmund, finding himself trapped, turned craven and
revealed the whole story. The real object of the spies was to get the
fullest possible details of the internal arrangements of a British
submarine of the latest type, and how well they had succeeded was shown
when we cast our net a little wider.
Directly Engstrom and Tegelmund were in custody, an innocent-looking
signal flag flew from the masthead of the submarine, and the officials
of the Surete ashore made their pounce. Thornton and Halbmayr were
seized at once at their hotel, and in their possession we found a
wonderful series of drawings in which many of the secrets of the
submarine were fully explained. A telegram to Paris brought about also
the arrest of Madame Bohman, and a few days later the German agents were
safely immured in the convict prison at Tours, where they were sent by
the sentence of a court-martial summoned immediately to deal with their
case. Their guilt in this particular case was too clear for any
possibility of denial, but I am glad to say that their arrest opened up
a way to us to deal the Hun Secret Service a blow from which it has
never fully recovered. Enormous piles of documents were seized and
carefully examined, with the result that numerous associates of Thornton
in England found themselves in durance vile "for the duration," and so
many fingers of the Hidden Hand were lopped off that the hand itself was
badly crippled for many months to come. How the fingers grew and were
again cut off I hope to tell at some later date.