SUMMARY. SPOILERS AHEAD:
Bianca is a wraith (ghost) and her boyfriend, Lucus, is a vampire. Their friend Balthazar helps them make the decision to return to Evernight Academy to help Lucus attempt to control his urges to kill humans. Before they can return, they are confronted by Lucus’ former vampire-hunting group, the Black Cross. His mother refuses to recognize that he is still him and not just some monster. After leaving the battle physically unscathed, they head to Evernight to help Lucus and find out why Ms. Bethany is attacking wraiths.
While at Evernight, Bianca is reunited with her friends and parents. Patrice shows her how to capture wraiths in a mirror. Her father tells her the back story between her mother and wraiths and why she is afraid of them. Lucus starts to trust Ms. Bethany because treats him well now that he is a vampire, which makes Bianca worry more because Ms. Bethany is setting wraith traps all around the school.
Though Bianca has been avoiding the other wraiths, she decides to go meet with the powerful one that had caused problems for the vampires earlier in the series. She finds that there is a sort of limbo for wraiths that she calls “the land of lost stuff” and head wraith, Christopher, lets her in on secrets. Ms. Bethany was Black Cross in her human days and Christopher (also Black Cross) was married to her. He explains to Bianca that she is meant to help wraiths that have trouble finding this place where they find some peace.
Lucus finds out that Ms. Bethany’s plan is to use a wraith to make herself human again. Since the wraith is the spirit part, and the vampire is the body part, together they make the vampire a human again. The group gets together to thwart this, especially since Bianca is the most powerful wraith and Ms. Bethany wants to use her.
There is a fight at the end. Mr. and Ms. Bethany die together in a firey blaze of glory, realizing that they still love each other. Bianca learns how to turn Lucus human again without killing herself. And they all live happily ever after.