The premise of the story centers on four people who have come to Toppers House to commit suicide. In this, the characters impact the development of the story. Hornby takes us inside their narratives. These explorations are the story. There is nothing else other than the lives of these four people. What compels them to consider suicide, how they are able to talk themselves off the ledge, and what steps they take in the wake of not committing suicide at the moment they intended helps to form the basis of the story. The characters impact the development of the story and the reader's understanding of it because it centers on them. They are the story. The narratives of the four main characters represents its development. When the story progresses, it is because some aspect of the characters is revealed. When more about them is known, more of the story is understood. Their interactions and the reader's understanding of their interactions is what drives the story and moves it. It is in this light where the characters hold a profound impact on the story.