This is the third book in this series, and they just keep getting better and better. Mac knows who her sister’s killer is, or thinks she does anyway, but she isn’t able to do anything about it yet. That’s not to say she’s not busy. The dropped-off-the-map parts of Dublin are growing and dark fae are all over the city so Mac is gathering information about fae in whatever way she can, honing her sidhe seer skills, trying to decide how far she can trust her human and not-so-human partners, and experimenting with ways--both almost comical and decidedly dark and risky--that she can protect herself. Some of her musings, on the meanings of liminal for instance, are beautiful and deep enough to read like philosophical poetry.