In the distant future, the Earth has destroyed itself. The remaining 'Solterrans', many generations later, run a planet, Raceworld, which hosts races in which the millions of planets of a galaxy-spanning empire compete. It's embedded as a major part of the galactic culture and even plays a role in diplomacy.

Solterrans have a reputation as totally fair--incorruptible--and it's Peter Christmas's role to maintain it, in order to keep Raceworld's place in society. He investigates any possibility of foul play, and has the final say in any disputes.

In this story, he attempts to find an equitable way for a bird that cannot fly, but can hover to enter the Non-Flying Avian races, proves that the equine animals in another race are actually intelligent, and it's their jockeys that are dumb animals, catches a group cheating by lying about the gravity their animals live under, and, finally, aids in early diplomacy with beings from the Magellanic Clouds by telling how the Solterrans came to run Raceworld.

He gives a stirring defense of Earth, which he insists is not dead, for all it is lost:

Something about this story really feels like classic scifi, with its myriad alien species engaging in human-like pursuits and interacting in human-like ways. It feels traditional even for 1969. The device of overlooking the alienness of the characters was used in Fritz Leiber's Later Than You Think in 1950, for example, where it serves as a twist ending--though not the only twist in that story. Still, it's enjoyable.