"I did not want my father's murderer to know that I was in England," answered Mercia. Then, with a kind of passionate break in her voice, she turned to me. "Oh, I have trusted you—I do trust you with all my heart! But tell me—ah, for pity's sake tell me!—who are you? You are so like Prado that even Guarez has been deceived."
I would have given much to be able to answer her questions, but like a black barrier my promise to Prado rose between us. I knew well that deeper even than her love for me was her passion for revenge on the man who had killed her father; and scoundrel as Prado might be, I had given him my word that for three weeks I would keep his secret.
"Just a few days longer, Mercia," I pleaded, "God knows I would tell you everything now if I could, but I have given my word, and I can't break it."
She did not answer for a moment Then slowly came the whispered words: "It shall be as you wish. I trust you always, because—because I love you."
A sudden furious blast from Billy, a violent swerve of the car that nearly took us into the hedge, and we were out on the road again with a pretty duet of abuse following us through the darkness.
Billy looked round with a smile. "Close shave that," he observed. "Fancy making love in the middle of the road!"
"Where are we?" I asked.
He pointed ahead to a clustered mass of lights that spread out long tentacles into the darkness.
"That's Romford, or ought to be. I shall have to slow up a bit now. We're getting into civilisation."
Through the apparently endless suburbs of London we slowly picked our way south-westwards. Billy steered with a cheerful confidence that was characteristic of him, never troubling to ask the way, but apparently contenting himself with an occasional glance at the stars to make sure that he was keeping in the right direction. As he observed to us over his shoulder, "You couldn't very well miss London, even if you tried."