Grell at his heels. Both men were plainly stirred by
some suppressed excitement. Green laid a note down in front of Foyle.

"Petrovska has killed herself," he exclaimed. "The matron found her
poisoned in her cell, a minute or so after I reached Malchester Row.
There was poison in one of her rings. She left this letter addressed to
you."

"Ah!" There was no betrayal of astonishment or any other emotion in the
superintendent's tone. He fingered the letter carelessly. "Won't you sit
down, Mr. Grell? No doubt you'll excuse us for a moment. Sit down,
Green."

He tore open the letter and glanced over the neat, delicate handwriting.
Thornton was leaning eagerly across the table. "A confession?" he asked.

"Yes--a confession," he replied. "Shall I read it aloud?" His eyes
rested for an instant on Robert Grell. "You may care to hear it," he
added.

"Go on," said Thornton.

Foyle spread the sheets on the table in front of him and began to read
in a steady, expressionless tone.

"Heldon Foyle, Esq., Superintendent, C.I.D., New Scotland Yard,
S.W.--Sir,--It would be futile, after what happened this morning, to
dispute any longer the correctness of the conclusions you have come to.
I killed Harry Goldenburg, and there is no need for any cant about
repentance. He deserved all he got. As for myself, I was fool enough to
step into a trap, and there is only one way out. I ought to have beaten
you, but as I failed, it may interest you to know the bare facts.

"Goldenburg was, as you guessed, my husband, though it was long since we
had lived together. Before I met him, however, I had become acquainted
with Mr. Grell--I think it was in Vienna. I was on the stage there, and
had a circle of admirers, of whom he became one. Whether you believe it
or not, I assure you, on the word of a dying woman, there was nothing
harmful in our intimacy. But letters passed, and his I kept.

"He disappeared out of my life after a while, and ultimately I met
Goldenburg. We were both living on our wits. I, of course, could not
fail to be struck by his astonishing likeness to Mr. Grell, and he told
me eventually of their relationship. There is no use beating about the
bush. Other people than Grell had written to me in the old days, and I
had my own methods of forcing them to keep me silent. In plain words, a
great part of my living was by blackmail, but I naturally acted very
delicately. Harry Goldenburg wormed his way into my confidence, and it
occu