'The Doll House' What does the narrator reveal about Aunt Beryl and her motives for treating the Kelveys so poorly? How does this contribute to the tone of the story?

At midnight thomas edison opened the door and continued his work, but to his surprise it was so late that he had to get some rest. but with his mind racing and his mind at sake he continued working. hours and hours went untill he got it. he had invented the worlds first lightbulb!