Both Alex and Kate continue passing messages to each other via the mailbox, and each watches its flag go up and down as the message leaves and the reply arrives as they wait at the mailbox. They cautiously look around each time the flag changes, hoping to somehow spot the other. It is in vain as they are alone at the mailbox. They then discover that they are living exactly two years apart. Their correspondence takes them through several events, including Alex finding a book, Jane Austen's "Persuasion", at a railway station where Kate said she would have lost it, and Alex taking Kate on a walking tour of his favorite places in Chicago via an annotated map that he leaves in the mailbox. Alex eventually meets Kate at her boyfriend's party, however he doesn't mention their exchange of letters because it had not happened to Kate yet. Kate later remembered the meeting as a vague memory in the past.