rdinand Knopf. This gentleman
was having his warm bath, preparatory to going to bed. So Robertson told
the detective. However, Mr. Knopf insisted on talking to Mr. Howard
through his bath-room door. Mr. Knopf thanked him for all the trouble he
was taking, and felt sure that he and Mr. Shipman would soon recover
possession of their diamonds, thanks to the persevering detective.

"He! he! he!" laughed the man in the corner. "Poor Mr. Howard. He
persevered--but got no farther; no, nor anyone else, for that matter.
Even I might not be able to convict the thieves if I told all I knew to
the police.

"Now, follow my reasoning, point by point," he added eagerly.

"Who knew of the presence of the diamonds in the house of Mr. Shipman
and Mr. Knopf? Firstly," he said, putting up an ugly claw-like finger,
"Mr. Shipman, then Mr. Knopf, then, presumably, the man Robertson."

"And the tramp?" said Polly.

"Leave the tramp alone for the present since he has vanished, and take
point number two. Mr. Shipman was drugged. That was pretty obvious; no
man under ordinary circumstances would, without waking, have his keys
abstracted and then replaced at his own bedside. Mr. Howard suggested
that the thief was armed with some anaesthetic; but how did the thief
get into Mr. Shipman's room without waking him from his natural sleep?
Is it not simpler to suppose that the thief had taken the precaution to
drug the jeweller _before_ the latter went to bed?"

"But--"

"Wait a moment, and take point number three. Though there was every
proof that Mr. Shipman had been in possession of L25,000 worth of goods
since Mr. Knopf had a cheque from him for that amount, there was no
proof that in Mr. Knopf's house there was even an odd stone worth a
sovereign.

"And then again," went on the scarecrow, getting more and more excited,
"did it ever strike you, or anybody else, that at _no_ time, while the
tramp was in custody, while all that searching examination was being
gone on with, no one ever saw Mr. Knopf and his man Robertson together
at the same time?

"Ah!" he continued, whilst suddenly the young girl seemed to see the
whole thing as in a vision, "they did not forget a single detail--follow
them with me, point by point. Two cunning scoundrels--geniuses they
should be called--well provided with some ill-gotten funds--but
determined on a grand _coup_. They play at respectability, for six
months, say. One is the master, the other the servant; they