Again a silence fell between us. I felt instinctively that she wished to confide in me, but dare not do so.
Therefore I exclaimed suddenly:
"Will you not tell me, Mrs. Petre, the identity of this great enemy of our friend—this woman? Upon information which you yourself may give, Digby's future entirely depends," I added earnestly.
"His future!" she echoed. "What do you mean?"
"I mean only that I am trying to clear his good name of the stigma now resting upon it."
The handsome woman bit her lip.
"No," she replied with a great effort. "I'm sorry—deeply sorry—but I am now in a most embarrassing position. I have made a vow to him, and that vow I cannot break without first obtaining his permission. I am upon my honour."
I was silent. What could I say?
This woman certainly knew something—something which, if revealed, would place me in possession of the truth of what had actually occurred at Harrington Gardens on that fatal night. If she spoke she might clear Phrida of all suspicion.
Suddenly, after a pause, I made up my mind to try and clear up one point—that serious, crucial point which had for days so obsessed me.