The film unfolds through three interconnected vignettes that revolve around a witch named Betty (Deborah Harry), who has kidnapped a young boy named Timmy (Matthew Lawrence). Betty holds Timmy captive with sinister plans to roast him and serve him at a dinner party for her fellow witches. To occupy himself during his confinement, Timmy is given an old, hefty book titled "Tales From the Darkside." When Betty reveals her dreadful intentions, Timmy cleverly begins to stall her by reading the stories from the book.
The first story he shares is titled "Lot 249." Set within the walls of a prestigious university, it follows a marginalized student, Bellingham ([Steve Buscemi]), who is tormented by two affluent peers, Susan ([Julianne Moore]) and Lee ([Robert Sedgwick]). The situation shifts when Andy (Christian Slater), Susan's brother, intervenes to help Bellingham with an ancient mummy that has arrived in the archaeology department. Bellingham discovers a scroll that possesses the power to resurrect the mummy, turning it into his servant. Fueled by vengeance for being denied a teaching position that involved both Susan and Lee, Bellingham brings the mummy to life to exact revenge. The mummy hunts down Lee in his apartment, brutally killing him, and later attacks Susan before they both meet their grim fates.
As tragedy befalls the rich students, Andy grows suspicious of Bellingham. He discovers Bellingham with the mummy and, after a confrontation, manages to incapacitate him. A chaotic battle ensues, and Andy burns the scroll, seemingly putting an end to Bellingham's dark ambitions. However, the story takes a chilling twist when Andy finds himself face-to-face with re-animated mummies of Susan and Lee.
Back in Betty's kitchen, her patience wears thin as she confronts Timmy about his attempts to stall his inevitable demise. Timmy, resourceful as ever, convinces her to listen to another tale, "Cat From Hell." This narrative tells the story of Halston ([David Johansen]), a hitman tasked by an elderly man in a wheelchair, Drogan ([William Hickey]), to eliminate a supposedly malevolent black cat. The cat is believed to be vengeful, having previously caused the deaths of Halston's sisters. As Halston encounters a series of misfortunes while attempting to kill the cat, it eventually turns the tables on him in a shocking, gruesome climax.
The final story explored is "Lover's Vow," featuring an artist named Preston ([James Remar]) plagued by a creative block. A chance encounter with a beautiful woman, Carola ([Rae Dawn Chong]), leads him down a new path of inspiration and love. However, his dark past haunts him—as he once witnessed a murder by a gargoyle, and the promise he made to remain silent has dire consequences. After ten long years, when Preston finally reveals the truth to Carola, she transforms into the very beast he had once encountered, resulting in a devastating recognition that their children share the same fate.
In a dramatic return to the witch's kitchen, Betty grows increasingly restless as she approaches Timmy with frightening intent. Desperate, Timmy improvises, using marbles to trip Betty, allowing him a critical opportunity to escape his confines. In a twist of fate, he manages to overpower Betty, shoving her into her own oven, thus turning the tables on his captor. With a victorious grin, he humorously interacts with the audience, asking, “Don't you just love happy endings?”
