se, and to put on last night's evening
shirt and collar and underclothing; very unlike him to have his watch in
the waistcoat pocket that was not lined with leather for its reception.
(In my first despatch I mentioned all these points, but neither I nor
any one else saw anything significant in them, when examining the body.)
It was very strange, in the existing domestic situation, that Manderson
should be communicative to his wife about his doings, especially at the
time of his going to bed, when he seldom spoke to her at all. It was
extraordinary that Manderson should leave his bedroom without his false
teeth.

All these thoughts, as I say, came flocking into my mind together, drawn
from various parts of my memory of the morning's inquiries and
observations. They had all presented themselves, in far less time than
it takes to read them as set down here, as I was turning over the shoes,
confirming my own certainty on the main point. And yet when I confronted
the definite idea that had sprung up suddenly and unsupported before
me,--_It was not Manderson who was in the house that night_--it seemed a
stark absurdity at the first formulating. It was certainly Manderson who
had dined at the house and gone out with Marlowe in the car. People had
seen him at close quarters. But was it he who returned at ten? That
question too seemed absurd enough. But I could not set it aside. It
seemed to me as if a faint light was beginning to creep over the whole
expanse of my mind, as it does over land at dawn, and that presently the
sun would be rising. I set myself to think over, one by one, the points
that had just occurred to me, so as to make out, if possible, why any
man masquerading as Manderson should have done these things that
Manderson would not have done.

I had not to cast about very long for the motive a man might have in
forcing his feet into Manderson's narrow shoes. The examination of
footmarks is very well understood by the police. But not only was the
man concerned to leave no footmarks of his own. He was concerned to
leave Manderson's, if any; his whole plan, if my guess was right, must
have been directed to producing the belief that Manderson was in the
place that night. Moreover, his plan did not turn upon leaving
footmarks. He meant to leave the shoes themselves, and he did so. The
maidservant had found them outside the bedroom door, as Manderson always
left his shoes, and had polished them, replacing them on the
s