n was not you, but Harry
Goldenburg.

"Previously, the time of the murder had been fixed by Professor Harding
as between ten and twelve. It was our business to find out who had been
with Harry Goldenburg at that time. Among those persons was the guilty
one."

"I can't see how that helped you at all," said Grell, his brows bent.

"In this way, and as a negative test. The alibi is a commonplace of the
criminal courts. Every person on whom clues might ultimately rest would
be eliminated from the investigation if it could be proved beyond doubt
that they were elsewhere at the time. You must remember, that we had not
only to find the murderer, but to produce evidence that would satisfy a
jury that we were right. But we worked, first of all, from such main
facts as we had. You were missing. Ivan was missing. A mysterious veiled
woman was missing. There was the pearl necklace that you had bought as a
wedding present for Lady Eileen. There was the strange dagger used in
the murder. There was the miniature of Lola on the dead man. These were
the chief heads. There were scores of minor things to be dealt with.

"The matter was complicated, too, by the dead man's clothes. In the
pockets, there were your personal belongings. A natural, but erroneous
assumption was that they were your clothes. There is not much scope for
individuality in evening dress. I confess I was misled and puzzled at
first, but a little thought afforded the explanation, and, in fact, it
would have been cleared up automatically in any event by the examination
of the garments.

"Now, subtlety may be an admirable thing, but it can be overdone. I have
never believed that, because a certain thing seems obvious, it is
necessarily wrong. It was reasonably certain that one, or all of the
missing persons, had knowledge of what had happened. It was extremely
probable that one of them was guilty. Our starting-point was to find
them. That was where organisation came in. The miniature helped me to
bluff Sir Ralph Fairfield into an admission that it was the portrait of
Lola of Vienna, and I purposely showed it to some newspaper men on a
pretext. One of them commented on the likeness to the Princess
Petrovska, who was staying at the Hotel Palatial, and I at once
telephoned to the hotel, and discovered that she was supposed to have
left at ten on the evening of the murder. A reference to the St.
Petersburg police gave us a few more facts about her. She became a
possibil