Louisa The Poisoner — Tanith Lee

Raised in a swamp by a mad witch, poor Louisa grew up with one goal in mind: to marry a wealthy man, then inherit his lands and money by whatever means it takes. And Louisa may well succeed, for she is a stunning beauty with the manners of an angel. At last she sets off to make her fortune . . . and with the help of her vial of undetectable poison, she soon finds her first victim. A dazzlingly dark fantasy, as only Tanith Lee could write it!