Oxford. Twenty minutes later he was robbing a lonely motorist
midway between Thame and Aylesbury. Then for forty minutes he appeared
to have been idle, his next two exploits taking place within five
minutes of each other, just after ten, in the neighbourhood of Amersham.
King's Langley was the scene of his next adventure, the time given being
about a quarter of an hour before he had overtaken us. In addition to
the particulars of these robberies there were a host of reports from
people who had seen the Pirate car pass them on the road. But there was
one notable omission from the latter list. Not from a single town was
there any record of the Pirate having been seen passing through it.

I got a map of the district, and, after studying the country carefully,
I was fain to confess that one of two things was certain: either the
Motor Pirate had the power to make his car invisible at will, or else he
had a truly phenomenal knowledge of the bye-roads. How he had even
managed to get to Oxford, after his exploits in the West of England,
without arrest, puzzled me. The car was so unique in shape that it
seemed bound to excite observation. It could not have been put up at any
hotel, any more than it could have been run through the country by
daylight, without exciting remark and its presence being chronicled.
What, then, had he done with it? The more I pondered the question the
more puzzled I became, and at the same time the more determined to seek
a solution of the mystery. But how? I made a dozen plans, all of which,
upon consideration, appeared so futile, that I gave up the game in
despair, and decided to see if my brain would not become clearer after I
had paid my promised visit to Colonel Maitland.

I did not find Miss Maitland alone, as I expected, or I might probably
have been tempted to confide my experience to her, and to have asked the
assistance of her woman's wit in putting me on the track of a solution
to the mystery. Mannering was with her. When I made my appearance in the
drawing-room, and found him enjoying a _tete-a-tete_, I cursed myself
for delaying my call and thus giving him such an opportunity. My temper
was not improved either by the discovery that they were sufficiently
engrossed in conversation to have been able very well to dispense with
my presence. I did not feel called upon to leave Mannering a clear
field, however, so I joined in the discussion, and tried my hardest to
be pleasant.

Of course, the