Everything, Everything is a young adult novel written by Nicola Yoon. The story follows a girl named Madeline who has never left her house due to a severe immunodeficiency disorder. Despite being confined indoors for most of her life, she develops a relationship with a boy named Olly, who moves in next door. As their connection grows stronger, Madeline begins to question the limitations placed upon her by her condition and the people around her. The book explores themes of love, identity, and self-discovery while navigating the challenges of living with a chronic illness.