Umm not to be rude but what book because you did not say?
Answer:
Definition of ingrained. 1 : forming a part of the essence or inmost being : deep-seated ingrained prejudice. 2 : worked into the grain or fiber. Other Words from ingrained Synonyms & Antonyms More Example Sentences Learn More about ingrained.
This causes the reader to simple wonder what he means by "nevermore." It creates a sense of mystery and wonder for the audience, causing them to yearn to learn more about this character.