ince his having been instructed to do so was certainly a part of
the plan, meant to clinch the alibi for Marlowe, I knew there must be an
explanation somewhere. If I could not find that explanation, my theory
was valueless. I must be able to show that at the time Martin went up to
bed the man who had shut himself in Manderson's bedroom might have been
many miles away on the road to Southampton.

I had, however, a pretty good idea already--as perhaps the reader of
these lines has by this time, if I have made myself clear--of how the
escape of the false Manderson before midnight had been contrived. But I
did not want what I was now about to do to be known. If I had chanced to
be discovered at work, there would have been no concealing the direction
of my suspicions. I resolved not to test them on this point until the
next day, during the opening proceedings at the inquest. This was to be
held, I knew, at the hotel, and I reckoned upon having White Gables to
myself so far as the principal inmates were concerned.

So in fact it happened. By the time the proceedings at the hotel had
begun I was hard at work at White Gables. I had a camera with me. I
made search, on principles well known to and commonly practised by the
police, and often enough by myself, for certain indications. Without
describing my search, I may say at once that I found and was able to
photograph two fresh fingerprints, very large and distinct, on the
polished front of the right-hand top drawer of the chest of drawers
in Manderson's bedroom; five more (among a number of smaller and less
recent impressions made by other hands) on the glasses of the French
window in Mrs Manderson's room, a window which always stood open at
night with a curtain before it; and three more upon the glass bowl in
which Manderson's dental plate had been found lying.

I took the bowl with me from White Gables. I took also a few articles
which I selected from Marlowe's bedroom, as bearing the most distinct
of the innumerable fingerprints which are always to be found upon toilet
articles in daily use. I already had in my possession, made upon leaves
cut from my pocket diary, some excellent fingerprints of Marlowe's
which he had made in my presence without knowing it. I had shown him the
leaves, asking if he recognized them; and the few seconds during which
he had held them in his fingers had sufficed to leave impressions which
I was afterwards able to bring out.

By six o'clock in