ow you say that Mrs. M'Gregor saw the car?"

"Yes, but she has retired."

"Her evidence will do to-morrow. We come to the man in the hood. Can
you give me any kind of a description of him?"

"He appeared to be tall, but a shadow is deceptive, and his
extraordinary costume would produce that effect, too. I can tell you
absolutely nothing further about him. Remember, I thought I was
dreaming. I could not credit my senses."

Inspector Dunbar glanced over the notes which he had made, then
returning the note-book and pen to his pocket, he took up the long
smoke-discoloured envelope and with a paper-knife which lay upon the
table slit one end open. Inserting two fingers, he drew out the second
envelope which the first enclosed. It was an ordinary commercial
envelope only notable by reason of the number, 30, appearing in large
red figures upon it and because it was sealed with black wax bearing
a weird-looking device:

Stuart bent over him intently as he slit this envelope in turn. Again,
he inserted two fingers--and brought forth the sole contents... a
plain piece of cardboard, roughly rectangular and obviously cut in
haste from the lid of a common cardboard box!

CHAPTER VIII

THE ASSISTANT COMMISSIONER'S THEORY

On the following morning Inspector Dunbar, having questioned Mrs.
M'Gregor respecting the car in which Mlle. Dorian had visited the
house and having elicited no other evidence than that it was "a fine
luxurious concern," the Inspector and Dr. Stuart prepared to set out
upon gruesome business. Mrs. M'Gregor was very favourably impressed
with the Inspector. "A grand, pairsonable body," she confided to
Stuart. "He'd look bonny in the kilt."

To an East-End mortuary the cab bore them, and they were led by a
constable in attendance to a stone-paved, ill-lighted apartment in
which a swathed form lay upon a long deal table. The spectacle
presented, when the covering was removed, was one to have shocked
less hardened nerves than those of Stuart and Dunbar; but the duties
of a police officer, like those of a medical man, not infrequently
necessitate such inspections. The two bent over the tragic flotsam of
the Thames unmoved and critical.

"H'm," said Stuart--"he's about the build, certainly. Hair iron-grey
and close cropped and he seems to have worn a beard. Now, let us see."

He bent, making a close inspection of the skull; then turned and
shook his head.

"No, Inspector," he said definitely. "This