Eternal Hearts. The final piece of their vampire hearts, #1

For five hundred years, they've searched for the one woman who could complete them. Vampires Nathaniel and Michael have loved each other for centuries-but without their third mate, the bond between them is incomplete. Immortal, powerful, and aching with loneliness, they've waited through generations for destiny to finally answer their call. Lady Abigail Tonnington is a young Regency widow who has only just reclaimed control of her life.
Freedom, independence, and a quiet future are all she desires. The last thing she expects is to be claimed by two dangerously alluring men. both of whom insist she is essential to their very survival. Their passion for each other is undeniable. Their desire for her is overwhelming. Abigail feels the pull of their love just as strongly-but there is a terrible price for joining them. To bind with her destined vampire mates, she must give up her humanity forever.
And once that choice is made, there is no going back. Torn between fear and longing, mortality and eternity, Abigail must decide what her heart truly wants. Because some loves are powerful enough to last forever.But only if she's willing to become immortal to keep it. A steamy Regency-era vampire why-choose romance filled with eternal mates, forbidden desire, MM romance, and a luscious historical paranormal setting.