She raised her eyes to mine. "Yes," she said, more calmly, "I do believe you. Should I be here if I didn't? I believe you against my own eyes, against the evidence of all San Luca, against reason itself. That is why I am trying to save you from the others."
A thrill of triumph shot through me at her words.
"Mercia," I whispered softly, "Mercia."
She lifted her hands again, as though to motion me back.
"But if you did not kill my father," she went on, "you know who did. Tell me the truth—ah, for God's sake, tell me the truth!"
The broken pleading of that piteous cry nearly shattered my resolve. But I had pledged my word to Northcote, and with a great effort I steeled myself to be true to it.
"I know nothing for certain," I said. "If the others believe me guilty, they are wrong. But why not leave them to take their own vengeance? They seem quite capable of it."
She drew herself up with a shudder. "It is too late now. There is only one escape from the League—death. When they came to me and told me that you were still alive, I joined them gladly, recklessly. I thought that at least I should be able to avenge my father. Then that night in Park Lane I learned, for the first time, that I was wrong. I deceived them, I lied to them. It would have been no good my telling them the truth: they would never have believed it. Even now, I think they suspect me."
Her half-incoherent sentences gave me my first glimpse of the real truth.
"Mercia," I said, "who do you think I am?"