As the center of Sorcery Studies for thousands of years, the Eldritch Academy of Enchantment, its staff, its alumni, and its students enjoy great renown in the world of monsters. The Macawbers regularly send members of the family there to study and most come out with a paper, but also major student loans to pay off. One feature of note within the academy's walls is the Library of Forbidden Spells, which houses instructions to magic that comes at the cost of a soul. This is why Beelzebub has an affinity towards the academy, though he's not a welcome guest, and the Library of Forbidden Spells is closed off to nearly everyone.
The Eldritch Academy of Enchantment is probably located somewhere in Europe. It's been around for millennia and is the go-to institution of higher learning for people interested in mastering magic. Its dean since forever is Specter McHex, who makes a point of providing the students with an encouraging environment. Moloculo Macawber, Morgana Macawber, and Globby are all alumni or students and Nasty even has a job as teacher at the academy. There's also Yorick, but how he is related to the academy is not specified.
The staff gladly arranges tours through the academy, but there's one chamber that is off-limits to all but a few. This is the Library of Forbidden Spells, where books are kept that provide a shortcut to mastering magic, skipping on the advanced math and physical labor involved in creating potions and powders that forms the backbone of sustainable magic. The catch is that the shortcut essentially is a deal with the devil and comes at the price of a soul. While the Eldritch Academy of Enchantment maintains the library, it does not approve of the kind of magic it grants access to and works to ensure no one has access to it. Unfortunately, Beelzebub can enter the academy and gain access for himself and whomever he thinks he can trick into a deal.
The reason Morgana Macawber turned to crime in the first place is to accumulate the money to pay off her student loans. Morgana is asked by the academy to do a presentation on a groundbreaking paper she's recently published: "Warts and Boils: Medieval Hexes Redefined for a New Age". For this special moment, Morgana invites her father, her aunt, her cousin, her boyfriend, and his daughter. On her father's advice, the group leaves Gosalyn in Nasty's care to experience a class on magic, specifically the creation of simple familiars, which also allows Darkwing's hands free to help Morgana set up her presentation. Gosalyn, however, lacks the patience to sit through the math and chemistry and accidentally creates chocolate pudding instead of a familiar. Humiliated by Nasty and the class for both her failure and being a normal, Gosalyn stomps out and meets with the janitor, who's actually Beelzebub in disguise and angling for Darkwing's soul. He gives her access to the Library of Forbidden Spells and turns her into an instant magic genius. Gosalyn flaunts her new powers and accidentally destroys Morgana's presentation tools. Morgana suspects that Gosalyn has been using one of the forbidden books, but Dean Specter McHex takes interest in her talents and arranges for Morgana's presentation to be made shorter so Gosalyn can do one of her own. With all her tools broken, Morgana's presentation is a disaster. Alone in the hallway, she discovers that Gosalyn indeed has been using forbidden spells and tries to warn her, but Beelzebub abducts her. During Gosalyn's presentation, he opens a gate to Hell, defeats the entire audience of the presentation, and gives Darkwing the choice to trade his soul for Morgana's. Darkwing accepts. Once Beelzebub has left, Morgana insists that Gosalyn can't have known what she was doing and, because this is true and therefore Beelzebub's contract void, the combined brainpower of the academy works on a plan to open a portal of their own and get Darkwing back. It is successful.