What is the climax of book The Prophet Yonwood by Jeanne DuPrau?

There seems to be a misunderstanding. There is no book titled "The Prophet Yonwood" by Jeanne DuPrau.

Jeanne DuPrau is known for the "City of Ember" series, but none of her works feature a character named "Yonwood."

Could you please double-check the title or author you are referring to?