Maintenance man Cleveland Heep is tasked with overseeing the myriad needs of his tenants in an apartment complex. One evening, he discovers that someone is sneaking in a swim after hours, a violation of the pool's rules. The pool cleaner also alerts him to unusual hair clumps filling the pool’s filter, sparking his curiosity. One particularly exhausting night, the sound of splashing beckons him to the pool, where he hopes to finally uncover the identity of this midnight swimmer. To his surprise, when he arrives, he finds the area empty, devoid of any footprints.
However, just as he’s about to give up, he hears splashes again and prepares to wait for the elusive swimmer to resurface. But fate takes an unexpected turn when he stumbles, hitting his head and rolling into the pool. When he awakens, he finds himself on his couch with a beautiful, nude young woman named Story across from him. She indicates that she was the one who brought him inside, and despite her fear of the outside world, she clings to him for comfort. In an effort to help her, he provides her with a shirt, but his attempts to engage her in conversation are met with limited success.
Once outside, Cleveland confronts a menacing creature, sending both him and Story fleeing back into the safety of his home. The plot thickens as Cleveland learns that Story is being hunted by a creature, which she can only describe as a dangerous entity. She hints at her identity as a "Narf." His curiosity piqued, Cleveland starts to inquire among his tenants about the significance of a Narf. He consults a young Asian student, Young-Soon Choi, who recalls hearing about a Narf in childhood stories told to her mother, although she can only recollect fragments of the tale.
As he fixes various repairs in the building, Cleveland takes the time to build rapport with his tenants while seeking deeper knowledge about the mysterious Narf. His inquiries lead him to seek stories from Young-Soon and her grandmother, who seems wary of his unorthodox interest in a childhood fairy tale. In a stroke of creativity, he starts to act juvenile to charm the grandmother into sharing more about the legend. To his delight, she relents, weaving a tapestry of lore that envelops Cleveland in its enchantment.
Meanwhile, Story wanders through Cleveland’s apartment, intrigued by the surroundings. While engrossed in a journal documenting Cleveland's personal tragedies, she inadvertently reveals her ability to communicate truths through selective gestures. It becomes evident that Story's mission is tied to a future illuminated by a great writer’s success, but she faces imminent danger from a creature called a Scrunt.
In a blend of suspense and absurdity, Cleveland attempts to protect Story with the aid of a walkie talkie, only for things to go awry when the Scrunt ambushes him. Just as disaster looms, an arrogant movie critic unexpectedly intervenes. Empowered by newfound clarity, Cleveland devises a plan involving his eclectic group of tenants to play pivotal roles in Story’s fate, seeking a “symbolist” to better understand the characters needed for the looming narrative.
As Cleveland races against time, he discovers not only the importance of their roles but also the weight of protecting Story from the cunning Scrunt that lurks in the shadows. In a climactic showdown, the guardian finally appears to confront the Scrunt. As the eagle’s call echoes, Cleveland bids a heartfelt farewell to Story, acknowledging her profound impact on his life, reminding him of the vibrant possibilities beyond his own self-imposed isolation. And just like that, she vanishes, leaving Cleveland transformed.
