I met Catherine Fisher just after the final draft of this book was submitted to its publisher. We had been talking about Corbenic and I had mentioned that I knew some of the places (and a rail journey) described in it. One of those places was the city of Bath. I mentioned that the descriptions were eminently recognisable. Catherine told me that her next book was set in Bath and she wanted to call it Aquae Sulis but her publisher wouldn't let her. She talked about how the story links three different time periods and, as our mutual liking for Alan Garner had come up previously, I immediately mentioned that Red Shift did the same thing. Catherine was a bit non-plussed: the influence had plainly been entirely unconcious.
This is that book - "Sulis" would be my favoured title - this one is a bit rubbish and "Aquae Sulis" sounds too stuffy. Sure enough there are three time periods and linked stories. Unlike Garner's book, the link is clearer but less brutal. (I don't think Fisher can be all that brutal to her protagonists.) I found that there are also echoes of The Owl Service, too.
Several thinly disguised historical figures appear but they may not be recognisable to people who don't know Bath well. This element amused me.
My response to the book is mixed; the writing is fine and the central mystery is, well, mysterious enough to have kept my interest but in her last two books Fisher has deveoped a taste for deeply flawed protagonists that are not very sympathetic. This I don't like. Despite the unconcious Garner homage there are enough interesting ideas that I feel a longer book that further developed them would not have been a bad idea - and it is very rare for me to say a book should be longer.
Incarceron remains my favourite Fisher novel - though there are still plenty I haven't read - it feels like her most original work.