Her nails send a zing of electric sensation down the back of his neck and into his spine. He's trapped by touch and tactility -- the smoothness of her skin, the taste of it beneath his mouth. He can feel the muscles of her inner thigh tighten the higher he goes and, being Castle, he takes advantage of every creative opportunity he can get his head around: a shallow, sharp bite to the inside of her thigh, smoothed immediately with a cool press of his lips.