Children of Twilight Series by Maggie Shayne

According to ancient prophecy, there's only one chance to avert the complete annihilation of the Undead. Twins James William and Brigit Poe, part human, part vampire, believe that they "are" that chance. In truth, the key lies with the reclusive--and mortal--scholar Lucy Lanfair.As Armageddon approaches, antivampire sentiment fuels a war neither side can win, driving James to abandon his moral code and draw Lucy into a deadly battle she wants no part of... moreAccording to ancient prophecy, there's only one chance to avert the complete annihilation of the Undead. Twins James William and Brigit Poe, part human, part vampire, believe that they "are" that chance. In truth, the key lies with the reclusive--and mortal--scholar Lucy Lanfair.As Armageddon approaches, antivampire sentiment fuels a war neither side can win, driving James to abandon his moral code and draw Lucy into a deadly battle she wants no part of.But Lucy soon realizes that she holds this powerful immortal's soul in her hands and that it's her destiny not only to stop a war but to save him from his inner darkness. If she fails, his race will die--and so will her heart. Is the power of love strong enough to save the world? less

Utanapishtim has paid dearly for the sin of creating the vampire race—imprisoned in a living death for centuries, driven to near madness. With a single white-hot glance, he immolates his descendants…and the vampire Armageddon begins.Beautiful and deadly Brigit Poe, not wholly vampire but fiercely loyal to that shared bloodline, is called into action. She abhors yet cannot deny her destiny: to vanquish the once-great king of the immortals and save the vampire race... moreUtanapishtim has paid dearly for the sin of creating the vampire race—imprisoned in a living death for centuries, driven to near madness. With a single white-hot glance, he immolates his descendants…and the vampire Armageddon begins.Beautiful and deadly Brigit Poe, not wholly vampire but fiercely loyal to that shared bloodline, is called into action. She abhors yet cannot deny her destiny: to vanquish the once-great king of the immortals and save the vampire race.Two warriors, equally matched in power and determination, are soon locked in an unwinnable battle, only to discover a passion so shocking it threatens every truth they've ever known—even as they must face one final battle that seems fated to end in death and heartbreak for them both. less