"It is more than rarity," Lan Wangji tells him. "If it is there as it is in my world, the connection between the Emperor's line and the tiānlóng is because the celestial ones are spiritual powers and guardians of the heavenly courts of the Jade Emperor. It is no accident that the Emperor on earth is known as the Son of Heaven."

He shakes his head. "There are different dragons in my world as well as yours, in the rivers and lakes and mountains and seas, but all are respected and greatly revered."

He nods to the rat and asks, "Would you prefer tea or wine?"