"We don't like to waste energy," Rhiow said. "If there's a way to do something without magic, that's the first priority. If the magic isn't vital, it isn't used. There's a limitation to how much energy is in the universe... and entropy is always running."

She put her whiskers forward in a smile and held her tail high, proud of her home. "Welcome to Grand Central," she said. "In my time the ehhif built it around sixty sunsround ago, as they count it, and it's still one of the busiest buildings in New York." She paused. "Well, it was," she amended, and there was no missing that note of regret and sorrow.