I'm not sure how writing this story overlapped with Lavinia, but I thought the Coastal city owed a lot to Ancient Rome. A kind of idealised more democratic Rome, which 17 years previously was invaded by a patriarchal montheistic desert tribe, who ban books and burn the library. I thought this was a bit soft-centred. I think she gives herself rather a gentle challenge.
The most interesting aspect is the oracular spirit of the library, which is a little bit scary and dangerous, but overall this is a fairly slight book I thought. I enjoyed it, but I speak as a committed fan.