en you intend to arrest her?"

"Yes."

"Do you know where she is?"

A quick consideration of this question led Barrant to the conclusion that
it would do no harm to let the lawyer know the scanty truth.

"She is in London. I have traced her to Paddington."

Mr. Brimsdown decided that, as the detective knew that much, it absolved
him from any obligation to betray the daughter of his dead client. His
feeling of relief unsealed his lips, and led him into an indiscretion.

"It seems incredible that she can be guilty." As he spoke the memory of
Sisily's tender and wistful face, as he had seen it that night, came back
to him.

"She had some justification, you know, if she was listening at the door
that afternoon," replied Barrant thoughtfully.

"It is hardly possible that she could have inflicted those marks on the
arm," Mr. Brimsdown said.

"How did you learn of them?" asked the detective quickly, in a changed
tone.

Too late Mr. Brimsdown realized that in contrast to his silence with
Charles Turold, he had now gone to the other extreme and said too much. He
hesitated, but his hesitation was useless before the swiftness of
Barrant's deduction.

"Was Charles Turold showing you the marks when I found you in the other
room?" he asked with a keen glance.

Mr. Brimsdown's admission of that fact was coupled with an assurance that
the young man had shown him the marks because he was convinced of Sisily's
innocence.

Barrant dismissed young Turold's opinions about the case with an impatient
shake of the head. "Who told him about the marks?" he said.

It was the thought which had occurred to Mr. Brimsdown at the time, but he
did not say so then. "How did you discover them?" he asked.

"When I was examining the body. But Charles Turold had no reason to
examine the body. Perhaps Dr. Ravenshaw told him. I must ask him."

"It is a terrible and ghastly crime," said Mr. Brimsdown, in an effort to
turn the mind of his companion in another direction. "There is something
about it that I do not understand--some deep mystery which has not yet
been fathomed. Was it really his daughter? If so, how did she escape from
the room and leave the door locked inside? Escape from these windows is
plainly impossible."

He crossed to the window, and stood for a moment looking down at a grey
sea tossing in futile restlessness. After an interval he said--

"Do you suspect Thalassa as well?"

The detective looked at him with a cautious