For as long as thirteen-year-old AMY can remember, BIBI has been by her side: her best friend, confidante, and avid defender, even though no one else can see her. With no friends, a well-meaning but awkward dad, and a dead mom who she doesn’t even remember, Amy is happy with just Bibi. Until KAYLA MACDONALD sits at her table at lunch, and the two begin a shaky friendship.
Bibi doesn’t trust Kayla, but Bibi doesn’t trust anyone, so Amy pushes away her concerns. But after Amy confides in her about Bibi’s existence, Kayla, worried, tells the school counselor, and soon the news is all over the school—and gets back to Amy’s dad. Fearing for her mental health, he sends her to a psychiatrist. But when the psychiatrist forces Amy to question whether she is just making Bibi up, Bibi pushes him down the stairs, breaking his leg. As far as everyone knows, Amy was the only one with him, and with her mental health already in question, she is sent to a psychiatric hospital.
Amy becomes more and more desperate—and unsure of Bibi’s existence—until Bibi breaks her out, seriously injuring several people in the process, proving to Amy that not only is she real, but she is dangerous. It is now clear that Bibi will hurt anyone who threatens her, and before she returns home, she searches for a way to banish her best friend. When Amy finally returns home, her dad, realizing his mistake, listens to her about Bibi and tries to repair their relationship. But these open discussions lead her to learn more about her mom, including the fact that she had a tattoo identical to a mark on Bibi’s hand. She realizes Bibi is what is left of her mom, and the idea of getting rid of her becomes far more terrifying.
After Kayla’s many failed attempts to apologize, Amy finally forgives her. But Bibi refuses to accept this, and tries to strangle Kayla before Amy stops her. Amy is now certain Bibi has to move on. Amy places herself in the middle of her worst fear and faces it head-on, proving to Bibi that she no longer needs her. Bibi protests at first, but finally accepts her identity and disappears. Amy mourns the loss of her best friend and her mom, but finally allows herself to accept Kayla, her first real, living friend, into her life.
(Thanks so much for any advice you're able to offer!)