My novella, The Mad Earl's Bride, is set between the time of Lord of Scoundrels and The Last Hellion. Like those two books, it's stayed in print for lo these many years. However, it has always been part of an anthology, —first, Three Weddings and a Kiss, then Three Times a Bride.
But earlier this summer, Avon brought the story out as a stand alone eBook, with an atmospheric new cover.
For a time, the book's been available at the nice price of $1.99. I'm not sure how long this will continue—so if you were thinking of getting a copy, now might be the time!