Darkhenge by Catherine Fisher

Some fantasy authors seem to rely too much on their readers not knowing the myths that inspire their stories. This one seemed to have promise--the back matter made me think that the main character Rob's comatose younger sister Chloe had gone into Faerie, and I got even more excited when the novel opened with the term "The Cauldron-Born" and a quote from The Book of Taliesin. That was the high point, though. Taliesin shows up, but doesn't seem especially trustworthy. This impression makes me want even more to root for his antagonist, Clare, who is also the goddess Ceridwen. But she doesn't seem very trustworthy, either; in fact, the only person who does is the priest, Mac, Rob's godfather. He seems to know more than he should, and this is never explained--in fact, a lot is never explained, from how Rob (the POV character) suddenly knows Dr. Kavanagh's first name to, despite repeated hints that it is significant, the identity of the King of the Unworld. Returning to my original point, the author also seems to take strange liberties with the Taliesin legend and stories of the Underworld. So much, in fact, that I think I would have enjoyed it more were it stripped of its mythological references. I just don't understand the point of having them if you're barely going to use them. I also would have been more content if I only vaguely knew the myths and didn't expect anything based on them. So overall, not an awful book, but one I certainly wouldn't recommend.