A Mastery of Monsters by Liselle Sambury

Ninth House meets Legendborn in this “bold and bloody” (Kirkus Reviews, starred review) first book in a dark academia fantasy series about a teen who’s willing to do anything to find her brother—even infiltrate a secret society full of monsters.

When August’s brother disappears before his sophomore semester, everyone thinks the stress of college got to him. But August knows her brother would never have left her voluntarily, especially not after their mother so recently went missing.
The only clue he left behind was a note telling her to stay safe and protect their remaining family. And after August is attacked by a ten-foot-tall creature with fur and claws, she realizes that her brother might be in more danger than she could have imagined.
Unfortunately for her, the only person with a connection to the mysterious creature is the bookish Virgil Hawthorne… and he knows about them because he is one. If he doesn’t find a partner to help control his true nature, he’ll lose his humanity and become a mindless beast—exactly what the secret society he’s grown up in would love to put down.

Virgil makes a proposition: August will join his society and partner with him, and in return, he’ll help her find her brother. And so August is plunged into a deadly competition to win one of the few coveted candidate spots, all while trying to accept a frightening reality: that monsters are real, and she has to learn to master them if she’s to have any hope of saving her brother.