Carrie and Sara Fleming are as different as two sisters can be. Both in high school, Carrie is an outgoing soccer jock, trying to navigate the minefield of Varsity sports - and dating. Sara is a talented musician, who wants to spend her senior year focusing on graduating and getting into a great music school. Both of their lives change forever when Sara inadvertently finds herself engaged to marry Lucien Gargouille, prince of an ancient race of gargoyles. Sara has no interest in marrying anyone, but a vow spoken in the moonlight has bound her to Luc - forever.
To make matters worse, there is a war brewing. For centuries, the gargoyles have protected mankind from all the dark forces in the world. But someone is making trouble, and trying to break the fragile treaty that has kept evil at bay, and Sara has become a target. Carrie sees the danger around her sister, but can only watch and wait, hoping that Luc and his Family can keep Sara safe. After all, this is what they were born to do - protect the world from vampires, and all the other creatures, who would try to break out of their darkness.
But when the enemy makes a daring move, it falls on Carrie to not only save her sister, but to keep the two worlds from crashing together.