"And expose her secret?" she asked. "Would he have acted as a gentleman had he done so? Does a man so lightly betray a woman's honour?"
"A woman's honour!" I gasped, staring at her, staggered as though she had struck me a blow. "What do you mean?"
"I mean nothing," was her cold reply. "Take it as you may, Mr. Royle, only be warned."
"But if Digby knew that she was worthless, he would surely have made some remark to arouse my suspicion?" I exclaimed.
"Why should he?" she queried. "A true gentleman does not usually expose a woman's secret."
I saw her point, and my heart sank within me. Were these scandalous allegations of hers based upon truth, or was she actuated by ill-feeling, perhaps, indeed, of jealousy?
We walked on again slowly until we reached St. James's Palace, and passed out into the end of Pall Mall, where it joined St. James's Street. Yet her attitude was one of complete mystery. I was uncertain whether the admission she had so unconsciously made regarding Phrida—that she was Digby's worst enemy—was the actual truth or not.
One thing was plain. This Mrs. Petre was a clever, far-seeing woman of the world, who had with great ingenuity held from me her knowledge of the crime.
A problem was, therefore, presented to me. By what means could she be aware of it? First, she had expected to meet Digby that evening; secondly, the letter I had brought was written before the assassination of the unknown girl.
How could she have obtained knowledge of the affair if it were not premeditated and hinted at in the letter I had so faithfully delivered?