Madeline has been stuck inside her entire life because of her disease SCID. Where you cannot go outside or you will get very sick and maybe not survive. Its very rare but her mom has spent every moment by her side, along with her nurse, Carla.
New neighbors move in, and the new teenage boy Olly catches Maddy's eye. Maddy receives his email and they talk for months. talking about how they would love to meet eachother and everything they wanted to do together.
After months of getting to know each other on email everyday, they finally end up hanging out multiple days out of the week, even if its dangerous for Madeline. Since Carla always let him come over while her mother was gone it was a bad idea. Maddy's mom eventually found out and banned Olly and Carla from her house.
They have fallen in love with each other. Madeline sneaks out with Olly and they go to Hawaii. She has the best days of her life and doesnt care if she dies. After a couple days in Hawaii Maddy gets very sick and her heart stops. But only for a bit, until she arrives back home.
Doctors say it was not because of her SCID, it was because of a viral infection down in hawaii. Maddy is confused and does lots of research. She ends up finding out she NEVER had the disease and her mom kept her inside for her enjoyment and loneliness ever since her husband and son died.
Madeline is free to rome the earth, but is very mad at her mother for wasting a big part of her life. after ignoring Olly for months after the accident she starts talking to Olly again and tells him the news. She buys a ticket to New York where Olly now lives and surprises her love one last time.