A Tangle Of Magicks - Stephanie Burgis

Second in a witty and irreverent adventure series set in Jane Austen times - with magic! I bit a chunk out of my apple and grinned at my older sister. 'I suppose I'd better come along and keep an eye on you. Just to keep everything proper.' When Kat Stephenson's family arrive in Bath in search of a suitor for her sister, it's not long before Kat discovers that the town is fizzing with wild and treacherous magic. Stumbling upon a plot to harness the magic in the Roman Baths, Kat finds that her brother has unwittingly become involved. To foil the plot and save her brother she must defy the Order of the Guardians and risk losing her magical powers, forever...