Heroine: Diana, Countess of Arradale.
Hero: Bey, Marquess of Rothgar.
It opens in Jun 1763 in London.

Book 5, and last, of the main Malloren World series.
Follows on from: Secrets of the Night.
Followed by: Winter Fire.

Devilish was first published in Apr 2000 by Signet [0451199979].
It won the RITA for Best Long Historical Romance at the 2001 RWA conference.
It was reissued in Jan 2006 [0451217942]. [Both covers are shown below]

More info on the book is available here: Devilish