Percy and Annabeth have been pen pals since the only way for them to communicate was through their mother's handwriting. One day, Percy's letters stop coming. Annabeth sends letter after letter, hoping that she'll get one in return, but she never does. Annabeth eventually forgets about Percy, until, when they are 16, they find each other at the same school. A few months go by without them figuring out the other's identity, until they work on a project together. After visiting her house, Percy realizes who Annabeth is. Fearing her reaction when she finds out who he is, he keeps the secret from her, and he starts to spend less time with her. Annabeth knows her new friend is distancing himself, but doesn't know why.