These are novels set in places like prestigious colleges, universities and boarding schools, with twisted storylines and characters. They go with the Dark Academia aesthetic.
The Uncorked Librarian says: "Books about dark academia feature grueling or cruel histories, gothic stories, spooky murders, mysteries, and cult-like behavior. Many of the characters possess unique qualities, quirks, secrets, and evil urges. Readers who seek out fantasy, speculative fiction, murder mysteries, and seriously creepy books will most likely enjoy dark academia novels. You'll find dark academia romance books as well as vampire, witch, and paranormal stories set across the globe."
Try not to stay up too late at night reading these.