Meg's best friend Oscar Dunleavy is missing and presumed dead after Meg left Ireland to go to New Zealand with her family. Meg is at the Church when Oscar's "best friend" Paloma.
It all started when Meg moves to New Zealand and leaves Oscar for six months. Meg and Oscar continue to communicate by sending letters back and fourth and keep in touch. When Meg left a new family moved into her house and Oscar became friends with his new neighbor Paloma, but their friendship is odd. Paloma doesn't want to appear to be friends with Oscar in public.
Meg wrote a love letter to Oscar but never sent it and kept it under her mattress. Little does Meg know Oscar also likes her too . But Paloma finds the letter in her room, Paloma likes Oscar too and wants him to like her. So Paloma changes the letter and gives it to Oscar.
Paloma makes up rumors and lies about Oscar. She bullies him and gets other kids to turn on him too. After Oscar realizing that Meg didn't like him like he liked her, he became more upset and confused. Oscar couldn't handle all the bullying so he ran away.
Meg does all she can to try to figure out where Oscar is and what happened to him at school. She soon figures out the Paloma is the cause behind this trouble and the way she treated Oscar.
Meg and Oscar's brother Stevie figure out that the letter that Meg sent to Oscar wasn't actually from Meg but that it was from Paloma. Meg figures out Oscar was devastated and that he feels the same way. She is more determined than ever to find him and make things right. Meg and Stevie go out to find Oscar and find him by the pier where they realize that everything is how its supposed to be.