Dark and Light Academia are both aesthetics and themes that have been popular in the 2020s. People sometimes define them in different ways, but what they both have in common is the romanticization of learning and love of books, literature, and the arts. As the names indicate, Light Academia tends to focus on lighter, more optimistic themes, like self-knowledge and self-discovery and the fun and adventure of learning, while Dark Academia tends to be more mysterious with deeper and more serious themes, sometimes focusing on issues of life and death. Because of the dark, mysterious themes and possible death, many Dark Academia books are also murder mysteries, although not all of them.
There are many videos and lists of recommendations for books in the Dark Academia aesthetic, and almost every video or list of recommendations covers certain ones that helped define this aesthetic - The Secret History by Donna Tartt, If We Were Villains by M. L. Rio, The Furies by Katie Lowe, Bunny by Mona Awad, and Catherine House by Elisabeth Thomas are major ones. However, there are older mystery books that also fit into this aesthetic, and I'd like to take moment to mention some of my favorites that don't get as much attention. (I also have a list of children's books that can fit the Academia aesthetics.)
Stories with an Academia setting tend to take place in traditional places of learning and study, such as schools (especially boarding schools), colleges, libraries, and museums, although they can take place anywhere where the characters can learn and enjoy books and the arts and search for the answers to some mystery or puzzle or explore their own identities or find some kind of deeper truth.
Mysteries set in colleges or at schools are nothing new, but one that I particularly think of is Gaudy Night by Dorothy L. Sayers, in the Lord Peter Wimsey series. In previous books in the series, Lord Peter Wimsey, an amateur detective in England, met and fell in love with a mystery novelist named Harriet Vane. When he first met her, she was on trial for the murder of her previous lover. Lord Peter managed to prove that she was innocent and find the real killer. He hoped that Harriet would agree to marry him after that, but she is still traumatized from the murder trial and from her last relationship, which was a manipulative one. She needs some time to get her life back in order and decide what she really wants. In spite of Lord Peter's repeated proposals, Harriet puts him off for a couple of books.
In Gaudy Night, Harriet revisits her old college at Oxford for a special reunion dinner. Reconnecting with old friends and professors reminds Harriet of happier times when she was a student and how much she loved the academic life. However, all is not well at the college. The dean confides in Harriet that someone has been playing nasty pranks, committing vandalism, and leaving poison pen notes for the staff. The dean trusts Harriet and asks her to stay at the college for a while as a research assistant and look into the matter because the dean doesn't know who to trust among the staff and residents. The mystery gives Harriet the chance she needs to reexamine her life and decide what she really wants. At first, the quiet college life of research and writing seems like a welcome escape from Harriet's troubles in the outside world and the suspicion that people still harbor toward her since her trial, but as she soon realizes, academia has its dark side, too. Lord Peter eventually arrives at the college himself and helps Harriet, and the two of them have a chance to get to know each other better and have an honest talk about their relationship and future.
I like the 1980s tv movie series based on this book and the preceding ones, too. You can sometimes see episodes or clips of this series on YouTube.
Books that involve characters who are professors or academics or even just people with a strong interest in literature or academic subjects can also be Dark Academia. Most of the Elizabeth Peters books could probably count because the mysteries that are set contemporary to the time when they were written often depend on the characters having knowledge of history or literature, and they usually have academic or literary professions.
I also enjoy the Poetic Death Mystery series by Diana Killian. In the first book, High Rhymes and Misdemeanors, Grace Hollister, a literature teacher from the United States, is visiting England to see the haunts of her favorite English Romantic poets in the Lake District, when she saves the life of an antiques dealer named Peter Fox. Someone tried to murder him by drowning him in a stream. People are after Peter because they think that he has something valuable that they refer to as "gewgaws." At first, Peter, who turns out to be a former jewel thief, doesn't even know what they're talking about. Grace figures out what they're after and their significance because of her knowledge of Lord Byron and his history. At the end of this mystery, Grace decides to stay in England and continues her relationship with Peter.
In the next book in the Poetic Death Mysteries, Verse of the Vampyre, Grace is acting as a consultant and research assistant for a production of The Vampyre, which was written by John Polidori, a friend of Lord Byron's, after the same ghost story contest that inspired Mary Shelley to write Frankenstein. Then, a woman is found dead at a masquerade ball with puncture wounds in her neck.
