<h2>CHAPTER XXI</h2>
<h3>WE PLAN AN AMBUSH</h3>
<div class='unindent'><span class="smcap">Forrest</span> had just concluded his story when the lights of
Thetford gleamed in our eyes. The time was 12.30.
The last train was gone. The inhabitants were all in
bed, and there we were, stranded with a broken car, and
no means of putting it right. Forrest would not despair,
however, and after some difficulty we managed, with the
assistance of the local police, to knock up a man who
was locally reputed to know all about motors. He was
a little surly at first, but the inducement I offered him to
make an attempt to put the transmission right, was sufficient
to dissipate his very natural disgust at being disturbed
in his beauty sleep. Fortunately his local reputation had
reasonable foundation. He was a very capable mechanician,
and the way he set about the job gave me great hopes
that the car would run as well as ever when he had
done with it. And my expectations were gratified. In
less than an hour he had completed the repairs. I paid
him and asked him to remain up for ten minutes in case
we had another breakdown, telling him that after that
period had elapsed, he would be at liberty to return to his<span class="pagenum"><SPAN name="Page_219" id="Page_219">[219]</SPAN></span>
bed. Whether he waited the ten minutes or not I do
not know, for by that time we were halfway to Newmarket,
flying through the darkness at a pace which two
months previously I would not have dared venture upon
in broad daylight. And right onward to St. Albans, we
kept it up, reaching the ancient town just as the birds
began to twitter in the hedges at the first grey light of
early dawn. At St. Albans we stopped at the police-station.
A man was waiting at the door.</div>
<p>"Any news?" asked Forrest.</p>
<p>The man shook his head.</p>
<p>"You know where to bring it?" asked my companion.</p>
<p>The man nodded.</p>
<p>"Let us get on home," said Forrest to me.</p>
<p>As I wheeled my vehicle into my yard I thought I
should drop. The strain of that rush through the night,
expecting every moment that something would give way,
had been tremendous, and the moment the tension was
relaxed I shook like an aspen leaf. When I tried to get
in at my own door I found I could not fit the latch-key,
and was obliged to hand it to the detective. He saw
what was the matter with me, and the moment we were
inside, he led the way to my study, thrust me down into
a chair and mixed me a whisky-and-soda. I was never
more grateful for a drink in my life. It pulled me
together, and in less time than I had conceived possible,
I felt as if I could have managed another seventy-five
miles without a halt.</p>
<p>The moment he saw my nerves were steady again,<span class="pagenum"><SPAN name="Page_220" id="Page_220">[220]</SPAN></span>
Forrest proposed that we should get something to eat. I
declared that I did not want anything.</p>
<p>"When you haven't time for sleep, the next best
thing is to feed well if you want to keep fit," he
remarked. "Besides, I am as hungry as a hunter has a
right to be."</p>
<p>"That settles it," I laughed. "We shall have to
forage for ourselves. The servants are all asleep."</p>
<p>We found our way to the larder and made a hearty
meal on a cold pie we found there; and directly we
had finished, we set out forthwith in the direction of
Mannering's home. As soon as we arrived opposite
the house, Forrest paused and gave a low whistle. It was
answered immediately by a man dressed as a labourer,
who made his appearance from behind the hedge opposite
the house.</p>
<p>"Any one been here to-night, Laver?" asked Forrest.</p>
<p>"No one," the man answered. "The servants
turned in about ten after locking up. No signs of any
one about the place since."</p>
<p>"That's all right," grunted Forrest. "We shall be
ready for him when he does come. Have you got the
tools?"</p>
<p>The man was proceeding to scramble through the
hedge when Forrest checked him.</p>
<p>"Better stay where you are," he advised. "Keep out
of sight, and if I whistle, come at once."</p>
<p>"All right, sir," replied the man, as he handed through
a gap in the hedge a small chamois leather bag.<span class="pagenum"><SPAN name="Page_221" id="Page_221">[221]</SPAN></span></p>
<p>I had no idea as to what steps Forrest proposed to
adopt in order to effect the arrest, so I asked him, and he
explained briefly his plan of campaign.</p>
<p>"One can see," he remarked, "that Mannering feels
so confident of the completeness of his disguise that he
will have no hesitation about returning. I am reckoning,
too, upon there being an element of truth in the story
he has told you about the construction of his motor, in
which case his own workshop would be the only place
where he would be able to refill his tank. We shall be
able to decide that point in a very few minutes. If we
do find any plant for the production of liquid gases, we can
count upon catching our man within a very few hours."</p>
<p>"Unless he smells a rat, and makes for some convenient
port and gets out of the country," I remarked.</p>
<p>"That eventuality is provided against," remarked the
detective. "His description is in the hands of the police
at every port in the kingdom, and even if he changes the
colour of his hair, I don't think he will manage to get
away. What I propose is, that we shall remain concealed
in his coach-house and await his return."</p>
<p>"How are we going to get in?" I inquired.</p>
<p>Forrest took a bunch of skeleton keys from the bag
Laver had handed to him and dangled them before his eyes.</p>
<p>"There's not a burglar in the kingdom is better
provided," he remarked, and set to work upon the lock
forthwith.</p>
<p>The lock was an ordinary one, and his efforts were
<span class="pagenum"><SPAN name="Page_222" id="Page_222">[222]</SPAN></span>speedily successful. The door swung open, and we
entered eagerly a bare, stone-paved coach-house. Opposite
the door by which we had entered from the road
was a similar door, which gave upon the inner yard. On
the left, a large sliding door had been fixed in place of the
wall which had divided the coach-house from the stables.
Relocking the door by which we had entered, Forrest
led the way to the door on the left. It was unfastened,
and as it swung back a cry of amazement sprang to
my lips.</p>
<p>"Hush—sh—sh!" said the detective warningly.</p>
<p>But I could not have repressed the cry, for there before
me stood a replica of the car I had seen on two occasions.
There was only one point of difference at first apparent.
The pirate car had been black. This one was built of
aluminium and gleamed silvery white. But although the
lines were very similar, I soon came to the conclusion that
the car we saw before us was not the one which the
Pirate had used when engaged upon his nefarious work.
One glance at the tyres convinced me that they had
never been upon the road, and I fancied that the wheels
were smaller and the lines of the body finer altogether.
I pointed these things out to Forrest, who, while agreeing
that this particular car could not have been the one
which had been responsible for holding up the "August
Personage" on the previous day, would not commit
himself further.</p>
<p>We did not spend much time upon a close examination
of the car, for the other contents of the building
claimed our attention. We found ourselves in a long<span class="pagenum"><SPAN name="Page_223" id="Page_223">[223]</SPAN></span>
workshop. There were no windows in the walls, but
the place was amply illuminated by a skylight which ran
along nearly the whole length of the northern slope of
the roof. On the right of the large door by which we
had entered the inner shop was a small room, which had
probably once served as a harness-room, for through this
another door gave on to the yard, though this exit was
evidently never used, for the door was fixed by screws.
The contents were a couple of broken chairs, and some
coats and rugs hung upon hooks upon the walls, together
with a miscellaneous assortment of odds and ends upon a
shelf. I gave merely a cursory glance at the contents of
this apartment, for my attention had been attracted by a
plant of machinery, which occupied the far end of the
large room. As it happened, I had once had an opportunity
of inspecting the laboratory of the Royal Institution, and
I recognized at once that Mannering had set up an installation
for the preparation of some one or other of the
liquid gases. Without this experience, I doubt whether
it would have been possible for me to guess even the
purpose for which the plant had been devised. As it
was, I had no hesitation in discovering the receiver into
which the liquid gas was distilled; and when I let a little
of the liquid with which it was filled run into a glass
which I found handy, and saw the air fall in a shower of
tiny snow-flakes as the stuff evaporated, I knew that
Mannering had told me the exact truth when he had
informed me that liquid hydrogen supplied the power for
his new car.<span class="pagenum"><SPAN name="Page_224" id="Page_224">[224]</SPAN></span></p>
<p>Once satisfied on this point, I examined the other
contents of the place. I do not think there is any need
to particularize all that we discovered, even if my memory
served me. Practically the workshop contained a sufficient
engineering equipment to build such a car as stood in the
centre, though I judged that there was no convenience
for the forging of the parts of the motor.</p>
<p>Still, as I pointed out to Forrest, there was nothing
in all these discoveries to negative the truth of the story
Mannering had told me about his being engaged in building
a car which should serve to outpace the Pirate car,
but he would not listen to any theorising on the subject.</p>
<p>"He can tell that story to the jury," he said, as he
significantly drew a pair of handcuffs from his pocket and
clinked them together. Then he proceeded to investigate
the contents of the harness-room, while I went back to
the new car and began a careful examination of the
engines. The whole mechanism was, however, so novel
to me, that I could only surmise as to the method of its
working. I did notice, however, that the driving and
steering gear varied very little from that of my own car,
so far as it was controlled by the levers and wheel, while
the breaks seemed to be particularly powerful. There
was only seating accommodation for two, and judging
from the size of the tank which was fitted behind the
seat, I judged that Mannering contemplated runs over
distances which would make large demands upon his
supply of liquid gas.</p>
<p>At the moment I made this discovery, I heard Forrest<span class="pagenum"><SPAN name="Page_225" id="Page_225">[225]</SPAN></span>
call to me in an excited whisper, and going across to
him, I found him contemplating with keen interest a
dirty piece of rope.</p>
<p>"Look here, Sutgrove," he said; "this is the piece of
cord with which he trussed me up on the occasion when
he dropped me into the pond. Compare it with this"—he
kicked a coil which lay at his feet—"and tell me if
they are not identical."</p>
<p>I examined them both, and came to the conclusion
that Forrest was correct in his supposition. Next, mounting
one of the chairs, he proceeded to rummage amongst
the rubbish piled on the shelf. A moment later he
observed triumphantly, albeit in subdued tones, "Another
piece of evidence," and descending from his perch, he
handed me a box of cartridges. A glance at the label
had apparently been enough, nevertheless, to make sure,
he searched again in his pocket, and produced the bullet
which had proved fatal to the poor victim at Towcester.
He compared it with one of the cartridges, and gave a
grunt of content. "I fancy we shall soon obtain sufficient
evidence to hang him," he murmured. Then a
shadow crossed his face. "What an infernal dunderhead
I have been not to suspect him before," he said, and
turning impatiently away, he replaced the box of cartridges
on the shelf, before renewing his systematic examination
of the rest of the contents of the room. The search
revealed nothing further, and at length he desisted.</p>
<p>All the while we were keenly on the alert to detect
any sound which should tell us of the approach of<span class="pagenum"><SPAN name="Page_226" id="Page_226">[226]</SPAN></span>
Mannering's car. But the minutes passed and grew into
hours without a sign. It must have been about five in
the morning when we had entered the coach-house, and
when I saw by my watch that it was nearly ten, I began
to think that in some way or another Mannering had got
warning of the danger that threatened him. I suggested
to Forrest that we might as well leave our hiding-place,
but he would not hear of it.</p>
<p>"I don't leave this building except in his company,
unless I hear that he has been captured elsewhere," he
declared obstinately. "At the same time, don't let me
detain you."</p>
<p>I wanted badly to see Evie, whom I thought might
be getting anxious concerning me; but I hardly liked
the idea of leaving Forrest to tackle Mannering alone
if he should return. However, my first desire triumphed,
so I persuaded Forrest to let me out of the door, promising
to return within as short a time as I could manage.</p>
<p>I hurried first to the Colonel's house, and had a
brief interview with the dear girl, telling her what had
happened and what was likely to happen in the near
future. Next, I went to my own place, and had a basket
packed with a plentiful luncheon, not forgetting to provide
a couple of bottles of champagne, and thus provided
I returned to the coach-house after an absence of less
than an hour.</p>
<p>When in response to my signal Forrest admitted me,
his eyes twinkled with satisfaction as he saw my burden.</p>
<p>"It is truly thoughtful of you," he remarked, as I<span class="pagenum"><SPAN name="Page_227" id="Page_227">[227]</SPAN></span>
lifted the lid of the basket and revealed the contents.
"I only hope our friend will not spoil our picnic by
arriving in the middle of it."</p>
<p>The better to avoid any such <i>contretemps</i>, we set about
our meal immediately with very good appetites. When
we had finished, I do not know how Forrest felt, but I
was confoundedly drowsy. I tried all sorts of tricks to
keep my eyes open, but the quiet of the place, the coolness,
and the subdued light of the saddle-room, where
Forrest thought it best for us to remain, were too much
for my powers of resistance and I dropped off to sleep.</p>
<p>I must have slumbered for a couple of hours, if not
three, when I was suddenly awakened by a hand placed
on my mouth, while a voice whispered in my ear—</p>
<p>"Wake up, man—wake up! There's no time to
lose."</p>
<p>I came to myself with a start. Forrest had hold of
me, and was shaking me violently. At the same moment
I became aware of the throb of an approaching motor.</p>
<p>Recognizing the sound, I turned to the detective.</p>
<p>"That's Mannering," I whispered.</p>
<p>"Yes," replied my companion. "I could swear to
the sound anywhere."</p>
<hr style="width: 65%;" /><p><span class="pagenum"><SPAN name="Page_228" id="Page_228">[228]</SPAN></span></p>
<div style="break-after:column;"></div><br />