Long out-of-print, a cult epistolary fantasy makes a welcome return. In an alternative 19th-century England touched by magic, Katherine and her beauteous younger sister are off to London. Kate has promised to keep in close touch with her cousin and bosom-bow Cecelia, and their beguiling correspondence comprises quite a tale. For Kate soon finds herself up to her ears in intrigue when the sorceress Miranda targets her for a spot of poisoning; meanwhile, back in the country, Cecy befriends the lovely Dorothea, who is reluctantly enchanting all the local swains. The two plots are entangled with the dastardly schemes of the wizard Sir Hilary regarding a certain chocolate pot, resulting in magical misadventures both comic and romantic. Kate and Cecy are witty, intelligent, and venturesome heroines, not above a bit of mendacity in a good cause, with nary a whiff of damsel-in-distress between them. Although Miranda and Sir Hilary exist mainly to be villainous, and the remaining characters serve mainly as plot devices or running jokes, this clever romp will appeal to fans of Regency romance and light fantasy. (Fantasy. YA)