It's always tricky to deal with real-life bigotry through fantastical surrogates -- just consider the X-Men, or how vampires/werewolves are treated in various books and TV shows. 
 So Laurie Forest had a tightrope to walk with "The Black Witch," a fantasy series set in a world where black-clad mages reign over a variety of oppressed magical minorities. Forest is an excellent writer with a vivid, haunting writing style and a world she clearly has put a great deal of thought and imagination into, but her characters and world-building start falling apart when the racism angle is addressed. 
 Raised in the wilderness. Elloren Gardner finds herself stuck between two possible paths -- her uncle wants her to go to Verpax University to make her own way, while her aunt Vyvian demands that she be wandfasted to charming Lukas Gray immediately. To pressure Elloren, Vyvian makes sure her stay at Verpax will be as miserable as possible, so she'll consent out of desperation. Not only does she have to work in the kitchens, but she's rooming with a pair of Icarals (which Gardnerian mages consider demonic). 
 And Ellen quickly finds that people at Verpax don't like her much -- some because she's a Gardnerian, and some for more personal reasons (like the cruel and beautiful Fallon Bane). As she tries to stay afloat in this hostile environment, she finds that she's being stalked by murderous Icarals -- and learns some of the ugly facts about the Gardnerian civilization and the other races they've oppressed. 
 First, the positive. Laurie Forest has undeniable skill as a writer, evoking a vaguely 19th-century world with a winding, complex history and a variety of clashing species -- Elves, Icarals, the vaguely humanish Kelts, the colorful Urisks -- each with their own history, and many little details and events of significance. And her writing style is quite luscious ("Ironwood trees are bursting with glowing Ironflowers that cast the road in their soft blue luminescence"), with some genuinely scary moments (when Elloren is assaulted by Icarals). 
 The problem is, this story is about racism. And racism is bad, mmmkay? 
 While it's a commendable message, it's handled with far too little subtlety here. "The Black Witch" takes place in a world where every single aspect of society is devoted to upholding racism ALL THE TIME -- the pseudo-Christian religion, the clothing, the school curriculum, and every single aspect of history explicitly revolves entirely around Nazi-like hatred of other races. Rather than making the world feel more three-dimensional, it instead flattens it down into one aspect of people's lives and thoughts. 
 As a result, Forest seems to be tackling weighty, complicated issues -- colonialism, racism, slavery, the malleability of history -- but she doesn't have the skill and subtlety to handle them that well. And by tying it explicitly into complex issues like religious faith, or depicting all racist offenders as religious zealots, she makes her handling of racism even more clumsy. Seriously, most religions don't have actual written doctrine supporting racism. Mostly people just interpret it to what they want. 
 And Elloren makes very little sense: she has supposedly been raised far apart from Gardnerian society, to the point where she barely knows about some aspects of it (such as sweatshops and Urisk labor camps). Yet she has all these racist views that are common among the other Gardnerians, which turn into outright hate when any non-Gardnerian isn't fawningly nice to her ("I barely hear her as hatred flares inside me, searing any speck of compassion"). I suspect this character was intended to be likable but flawed, and we were supposed to follow her as she learns that racism is bad MMMKAY? 
 But Elloren isn't likable enough for this. She's naive, dim, whiny, and most of her interactions can be summed up as "He's so hawt," "Someone's being mean to meeeee!" and "I didn't know any better!" And she's also wildly inconsistent, being both ignorant AND knowledgeable about the dynamics of this world, and immediately going from super-pious to discarding her religion because... well, because her brother is gay. Which she also responds to in an awful way, I might add. 
 The other characters are just as subtle -- Fallon Bane is basically a less interesting genderflip of Draco Malfoy, who apparently has no purpose in her life except torturing others; Lukas isn't much better. Most of Elloren's friends are fairly pale and uninteresting, and the Kelt boy exists merely to be hot. The only ones who stick out are the Elves and Icarals. 
 "The Black Witch" aims high with a story about racism and how it can infect everything in a society, but falls short in its actual handling of racism... not to mention the flimsy main characters.