In this novella, Meyer provides the backstory for the villain of the Lunar Chronicles series, and does so beautifully. Unlike many other stories that show that the villain is really just ~misunderstood~ or was misunderstood until s/he became evil, Fairest shows us a person who is truly awful and has no idea how awful she is. Levana is capable of justifying anything to herself, but at no point does Meyer try to justify Levana to the reader, which is a wonderful balancing act for a writer to pull off. In the few moments when Levana understands that what she's doing truly is terrible, she manages to do something even more terrible to "fix" the problem she's created. Despite the fact that Levana does actually have a pretty horrific childhood, it's clear that her choices are still her choices and that she's given every opportunity to make the right ones--and doesn't. 
 There's a new obsession with releasing lots of companion novellas to young adult series, and fewer of those are worth reading than are written, but this is one of the good ones.