Julie Kagawa said this quote

Having second thoughts?” Puck’s voice was soft and dangerous, a far cry from his normal flippancy. “I thought we put this behind us for now.”“Never,” I said, matching his stare. “I can’t ever take it back, Goodfellow. I’m still going to kill you. I swore to her I would.” Lighting flickered overhead, and thunder rumbled in the distance as we faced each other with narrowed eyes. “One day,” I said softly. “One day you’ll look up, and I’ll be there. That’s the only ending for us. Don’t ever forget.