"Crucial to grafting," Claudius says, with all delight. It's a delight few see unless he's scored some point in a social game he's playing, embarrassed someone or carried off some subtle manipulation. Except, of course, it's about plants. (Plants don't have social lives, except he has read other books that suggest they communicate, and infodumped to Galahad about those, too.) "Grafting takes a cutting from one plant and joins it to another. If one plant has stronger roots, say, then grafting a cutting to it gives the cutting a better chance to survive. We can try that, too. In a way, it's fitting. We've all been grafted a bit here, and Lan Wangji ... he's a traditional man, but I believe he appreciates the benefits of adaptation." But don't get Claudius started on Darwin. That wasn't a purposeful discovery, but it was a fascinating one, and one Claudius spent some time puzzling over, when he was so certain the properties of different species of plants were influenced by celestial bodies, put there by God.

The celestial bodies probably are still relevant. Darwin just hadn't figured that part out.