d."

I did not see any sign of emotion on Strange's face. He stepped back in
silence to allow us to enter. Then closing the big door after us, he led
the way along a carpeted hall to a small, ill-lighted room just beyond.
Here he motioned us to be seated, he himself standing upright beside the
table, facing us.

"From Scotland Yard," he said, and the tone was heavy with dull sarcasm.
"I am at your service, Mr. Hartnett."

* * * * *

And now, for the first time, I wondered just why Drake had insisted on
my coming here to this gloomy house in Mate Lane. Why he had so
deliberately arranged a substitute so that Michael Strange should not
come face to face with him directly. Evidently Hartnett had been
carefully instructed as to his course of action--but why this seemingly
unnecessary caution on Drake's part? And now, after we had gained
admission, what excuse would Hartnett offer for the intrusion? Surely he
would not follow the bull-headed role of a common policeman!

There was no anger, no attempt at dramatics, in Hartnett's voice. He
looked quietly up at our host.

"Dr. Strange," he said at length, "I have come to you for your
assistance. Last night, some time after midnight, Franklin White was
strangled to death. He was murdered, according to substantial evidence,
by the girl he was going to marry--Margot Vernee. I come to you because
you know this girl rather well, and can perhaps help Scotland Yard in
finding her motive for killing White."

Michael Strange said nothing. He stood there, scowling down at my
companion in silence. And I, too, I must admit, turned upon Hartnett
with a stare of bewilderment. His accusation of Margot had brought a
sense of horror to me. I had expected almost anything from him, even to
a mad accusation of Strange himself. But I had hardly foreseen this cold
blooded declaration.

"You understand, Doctor," Hartnett went on, in that same ironical drawl,
"that we do not believe Margot Vernee did this thing herself. She had a
companion, undoubtedly, one who accompanied her to the house on After
Street, and assisted her in the crime. Who that companion was, we are
not sure; but there is decidedly a case of suspicion against a certain
young London sportsman. This fellow is known to have prowled about the
White mansion both on the night of the murder and the night before."

* * * * *

Hartnett glanced up casually. Strange's fac