Elizabeth J. Crown [Elly] and Alexander J. Crown [Alex] are twin sister and brother. The night of their 18th birthday Elly gets into a car accident which result in her heart transplant. But after the heart transplant, things start changing. The vampire student of Elly's class start hearing strange sounds. In the end he found that that was the sound of a beating heart and it was coming either form Elly or Alex. This beating heart lead them to changes, changes they don't want.