The atmosphere or feeling in a literary work is called

the verbal in this sentence is an infinitive. when you want to know the reason of an action, you simply ask the question "why? ". once you know the reason you can answer with "because".

many times we don´t use the word "because" but we can use another expression and that is an "infinitive of purpose". example:

-why did your brother bring a book?

-he brought a book to study.

in the answer above you can see an example of an infinitive sentence, just like in the example of your text. "he couldn´t run fast enough to beat his older sister". so, the answer is infinitive.

the story is told by a young girl who loves reading journals and listening to radio. she seems as an attentive and joyful girl. however, when the story unravels later this turns out to be upside down. she is actually a naive girl.  

she meets with a boy while skating and he tells her that will call her. the problem of the story epitomizes here because he never calls and she acknowledges the fact that she is not a foolish. indeed, her communication with the boy identifies their relationship after all. it is somehow the struggle between emotional and physical engagement which we can only observe the latter one from the boy’s side. so that, the conflict is disclosed how it has been presented in the beginning where the girl believes that she is not a fool. the reader questions her self-confidence and understanding, as well as her sincerity.