Lily Bainbridge has had enough of her life with her stepfather. Her mother, the only link with him, is now dead. Lily stages her own death and escapes to London, dressed as a boy, to a life of freedom. On the way, she meets up with Ethan Andarton, who is the only person to see through her disguise and he thwarts her plans. But once they reach London, she leaves him and does not expect to see him again.

Ethan Andarton, by a quirk of fate, is the Marquis of Vessey. For family duty he has agreed to a marriage of convenience, a marriage that will allow him to continue in his previous life as a rake quite freely. When he meets Lily, he is intrigued enough to want her for his mistress.

As time progresses, both Ethan and Lily realize they want more than just an affair - they want forever. They just have to find a way to be together when fate and parents try to keep them apart forever.

The Accidental Mistress  is not a book that wants to be put down once started. Lily is perfect, instead of whining about what is wrong in her life, she goes about fixing her problems on her own without waiting for life to give her ‘her due’ as so many historical books seem wont to do. Lily fast became one of my favorite historical characters of all time. Ethan was spoiled and aristocratic, which given the time period made sense. As The Accidental Mistress progressed, both Lily and Ethan developed and fought with themselves and their future. The only problem I had was the suddenness of one plot twist, which I felt could have been developed a bit more.  That said, I totally enjoyed how this twist and the book as a whole ended.