KNOX Grayson called me from the arrivals hall to tell me he'd identified the twins from thirty feet away without having met them. "The boy's got your forehead," he said. "And the girl did this thing with her chin when she saw me carrying the wolves. That's your chin, Knox. You make that face when someone brings you a problem you already solved." He was right on both counts. By the time I got down to Riley's apartment Grayson had been installed on the living room floor for approximately seven minutes and the twins had accepted him as a permanent fixture of their lives. Hunter was explaining the structural limitations of a block tower with the focused intensity of a small engineer, and Grayson — who had spent the last four years handling pack security negotiations and was not known for p

