Luke enters, Josephine's life and they form an intense relationship that slowly builds into more. Luke is desperate to help, Josephine. He wants to find out what happens to her on the same day every year. Luke also harbors a deep secret that could unravel the relationship, he has built with Josephine.
Josephine is in an institution and her therapist is convinced that, Luke is a figment of her imagination. He also doesn't believe that she becomes someone or something else once a year. She is desperate to prove that she needs to be isolated before she kills others and that Luke is real. In order to do so, she tells him her story and it is quite interesting.
The character's are well developed and the book ends on a cliffhanger, leaving you anxious for the next installation.