This post is for the seventh of SFF.SE's new series of topic challenges, encouraging the site's community to take part together in asking and answering questions on a particular topic each month. According to community votes on the topic challenge proposals thread, the July 2021 topic challenge is going to be devoted to an ongoing urban fantasy series starting from 2011:
Rivers of London
What's a topic challenge and how do I take part?
See Announcing a Topic Challenge program for SFF.SE, and also this main meta post. In short, during July 2021 we should all try to: either read Rivers of London (or not, if you've already read it) and ask interesting questions about it, or help out by answering other people's questions about them.
Participation is not obligatory in any sense, but those who participate will be forever remembered in the annals of our history. We'll keep a list of all Rivers of London questions asked during July 2021 in an answer to this meta post. At the end of the month, I'll collate some data like highest-scoring question, most-viewed question, highest-scoring answer, etc. There won't be any real-world rewards like in the old days when Stack Exchange was smaller and more generous, but I'll be awarding at least one bounty after the end of the month (assuming there's at least one good answer posted).
Future topic challenges will be chosen by community votes, so come over and propose or vote on suggestions at:
Propose future topics for SFF topic challenges!
(The Rivers of London answer will be deleted from that thread at the start of July, since already chosen topics shouldn't stick at the top of the thread and distract people from those still to be voted on.)