It reveals Culture, a world ruled by benevolent AI (at least sympathetic to humanity), a wonderfully complex world but so interesting.
We discover Gurgeh, champion of the game, trapped by the IA to force him to participate in a new game, dangerous, for the benefit of culture policy.
One comes to get excited about this game, its handling by Gurgeh, his victories, his fight.
The maneuvers, political intrigue (on all sides), low blows.
We do not get bored for a second.