The Accidental Mistress

The Accidental Mistress is a historical romance by the American writer Tracy Anne Warren, published in 2007 and part of her Mistress trilogy.

Lily Bainbridge is twenty and facing a marriage arranged for her, so she does something drastic: she stages her own death and leaves for London disguised as a boy. Once there she puts together a second identity as a widow, which would let her live independently in a society that offers very few ways for a woman to do that, and the arrangement holds until a marquis takes an interest in her. He wants her as his mistress, and she is not willing to hand over the little she has left, which leaves the two of them negotiating in a book where the obstacle is not a rival but the truth about who she is. Warren writes the novel as part of a trilogy about women who are each living under a name that is not entirely theirs.

It is the second book of that trilogy, and the same circle of friends and the same London season carry over from the first.