In 12th century Ireland, a sorceror is sent on a mission by the goddess Morrigan to destroy a powerful vampire, with the help of a shape-changer, a scholar, a warrior, a vampire, and a 21st century witch.

As the powerful vampire Lilith prepares to quench her thirst for destruction by unleashing her fury in battle, a medieval sorcerer, one of the circle of six charged by the goddess Morrigan, must travel through time to stop her.

"The Circle Trilogy begins with an epic tale that breaks down the boundaries between reality and the otherworldly, while forging together the passions of the men and women caught in a battle for the fate of humanity... In the last days of high summer, with lightning striking blue in a black sky, the sorcerer stood on a high cliff overlooking the raging sea... Belting out his grief into the storm, Hoyt Mac Cionaoith rails against the evil that has torn his twin brother from their family's embrace. Her name is Lilith. Existing for over a thousand years, she has lured countless men to an immortal doom with her soul-stealing kiss. But now, this woman known as vampire will stop at nothing until she rules this world--and those beyond it... Hoyt is no match for the dark siren. But his powers come from the goddess Morrigan, and it is through her that he will get his chance at vengeance. At Morrigan's charge, he must gather five others to form a ring of power strong enough to overcome Lilith. A