"

"Nepcote may have been the man who offered the diamond to Wendover."

"That is impossible. Wendover says that man called some days before the
murder."

"Still, it may have been Nepcote."

"That goes beyond me," said Caldew, with a puzzled look. "What are you
implying?"

"Nothing at present. Every step in this case convinces me that we are
faced with a very deep mystery. It isn't worth while to hazard a guess,
because guessing is always unsatisfactory."

"Perhaps we had better try and get a little more out of Wendover," said
Caldew.

"That would be merely waste of time. He has not got the necklace, and he
is unable to describe the man who offered him the diamond. I believe now
that it was Nepcote, but that doesn't matter, one way or another. It is
far more important to know that he came here to-day to watch for us.
That implies that he had reason to fear investigations about the
necklace. The inference to be drawn is that Nepcote is responsible for
the disappearance of the necklace, and is, therefore, deeply implicated
in the murder."

"Perhaps it was not Nepcote that you saw?" suggested Caldew. He felt
that the remark was a feeble one, but he was bewildered by the sudden
turn of events, and in a frame of mind which clutches at straws.

"Put that doubt out of your mind," said Colwyn. "I saw his face
distinctly. He had disappeared by the time I got down. The alley where
he was standing commanded a view of the entrance of this building. I
ascertained that by standing in the same spot. His flight is another
proof--though that was not needed--of his guilty knowledge and
complicity in this murder. Why should he run away? According to his own
story last night he had nothing to fear. But now, by his own actions, he
has brought the utmost suspicion on himself."

"I suppose it is no use searching about here for him?" remarked Caldew,
glancing gloomily out of the doorway.

"Not in the least. The neighbourhood is a warren of alleys and side
streets from here to Grays Inn Road."

"Then I shall go up to his flat at once," said Caldew. "He has not had
time to go back."

"He will not return to his flat. We have seen the last of him until we
catch him. He has had two warnings, and he is not likely to be guilty of
the folly of waiting to see whether lightning strikes thrice in the same
spot. He will get away for good, this time, if he can. Nevertheless it
is worth while going to the flat. We may pick up some points th