As the plan goes into action to race the horse, the narrator sleeps up in the attic with Otis, another young boy at the house who is very different than Lucius. When Otis reveals that he has made money by drilling peepholes into the rooms and charged others to spy on what was going on with Miss Corrie and her customers, Lucius feels rage and disgust and attacks him. Otis, however, has a knife and while he takes a bad beating, Lucius grabs the knife away and is badly cut. Miss Corrie comes up to dress the wound and Otis has told her what the fight was about. She is obviously moved by Lucius' actions.
Corrie's promise not to prostitute herself is made because she has seen someone else defend her virtue. Lucius is a product of his upbringing and while he doesn't know exactly what's going on here, he knows that Otis' actions played on the evil side of man's nature, and in the process, further degraded Miss Corrie's own. He is learning fast:
Lucius has resolved to his understanding that his taking the car with Boon and taking off was a struggle that Non-virtue seemed to make all too easy, his lies were corroborated just by circumstance and helped pave his path to the forbidden. With this encounter, he has seen that things happen just as easily when one does the right thing. Just as Miss Corrie has learned that good does exist, so has Lucius and they have formed a bond in their acceptance.
The Lost Children: A Charity Anthology