hat can in any way affect him."

"You could give us information, then, that would affect Miss Dare?" was
the quick retort. "Now, I say," the astute detective declared, as the
prisoner gave an almost imperceptible start, "that whatever your
information is, Miss Dare is not guilty."

"You say it!" exclaimed the prisoner. "What does your opinion amount to
if you haven't heard the evidence against her?"

"There is no evidence against her but what is purely circumstantial."

"How do you know that?"

"Because she is innocent. Circumstantial evidence may exist alike
against the innocent and the guilty; real evidence only against the
guilty. I mean to say that as I am firmly convinced Miss Dare once
regarded you as guilty of this crime, I must be equally convinced she
didn't commit it herself. This is unanswerable."

"You have stated that before."

"I know it; but I want you to see the force of it; because, once
convinced with me that Miss Dare is innocent, you will be willing to
tell all you know, even what apparently implicates her."

Silence answered this remark.

"You didn't _see_ her strike the blow?"

Mansell roused indignantly.

"No, of course not!" he cried.

"You did not see her with your aunt that moment you fled from the house
immediately before the murder!"

"I didn't _see_ her."

That emphasis, unconscious, perhaps, was fatal. Gryce, who never lost
any thing, darted on this small gleam of advantage as a hungry pike
darts upon an innocent minnow.

"But you thought you heard her," he cried; "her voice, or her laugh, or
perhaps merely the rustle of her dress in another room?"

"No," said Mansell, "I didn't _hear_ her."

"Of course not," was the instantaneous reply. "But something said or
done by somebody--a something which amounts to nothing as
evidence--gives you to understand she was there, and so you hold your
tongue for fear of compromising her."

"Amounts to nothing as evidence?" echoed Mansell. "How do you know
that?"

"Because Miss Dare was not in the house with your aunt at that time.
Miss Dare was in Professor Darling's observatory, a mile or so away."

"Does she say that?"

"We will _prove_ that."

Aroused, excited, the prisoner turned his flashing blue eyes on the
detective.

"I should be glad to have you," he said.

"But you must first tell me in what room you were when you received this
intimation of Miss Dare's presence?"

"I was in no room; I was on the stone step outsi