y narrative, and to show you
your conduct from my point of view, I no sooner release you than you
stare like a lunatic at my anatomical cases and dash wildly out, to
return full of menace in your tone and attitude. Why?"

"Doctor van Heerden, when I came into your flat there were three
anatomical cases at the end of that room. When I came out there were
two. What happened to the third whilst I was locked in the room?"

Doctor van Heerden shook his head pityingly.

"I am afraid, I am very much afraid, that you are not right in your
head," he said, and nodded toward the place where the cases stood.

Beale followed the direction of his head and gasped, for there were
three cases.

"I admit that I deceived you when I said they contained specimens. As a
matter of fact, they are empty," said the doctor. "If you like to
inspect them, you can. You may find some--clue!"

Beale wanted no invitation. He walked to the cases one by one and
sounded them. Their lids were screwed on but the screws were dummies. He
found in the side of each a minute hole under the cover of the lid and,
taking out his knife, he pressed in the bodkin with which the knife was
equipped and with a click the lid flew open. The box was empty. The
second one answered the same test and was also empty. The third gave no
better result. He flashed his lamp on the bottom of the box, but there
was no trace of footmarks.

"Are you satisfied?" asked the doctor.

"Far from satisfied," said Beale, and with no other word he walked out
and down the stairs again.

Half-way down he saw something lying on one of the stairs and picked it
up. It was a shoe, the fellow of that which he had in his pocket, and it
had not been there when he came up.

* * * * *

Oliva Cresswell had read the story of the crime in the _Post Record_,
had folded up the paper with a little shiver and was at her tiny
writing-bureau when a knock came at the door. It was Dr. van Heerden.

"Can I come in for a moment?" he asked.

She hesitated.

"I shan't eat you," he smiled, "but I am so distressed by what has
happened and I feel that an explanation is due to you."

"I shouldn't trouble about that," she smiled, "but if you want to come
in, please do."

She closed the door behind him and left the light burning in the hall.
She did not ask him to sit down.

"You have seen the account in the _Post Record_?" he asked.

She nodded.

"And I suppose you are r