The fourth episode of "Head Over Heels" kicks off with the reverberations of Gyeon-woo's reciprocal gesture, leaving Sung-ah and Gyeon-woo both distracted and entangled in the nascent threads of their burgeoning romance. As they grapple with the turbulence of their newfound emotions, Sung-ah finds herself aiding her spiritual mother in orchestrating another ritual, aiming to expel the malevolent force that has taken refuge within their abode. During this revealing moment, it comes to light that Sung-ah has merely eight days left to uphold her duty of safeguarding Gyeon-woo.
The narrative shifts to the haunted house where, coincidentally, a pair of online streamers arrive, eager to broadcast live from this infamous location. Sung-ah, cognizant of the perilous consequences, fiercely warns them away, her tone a blend of urgency and severity. Undeterred, the duo decides to sneak back into the house after the shamans' departure. Consequently, one of the streamers falls prey to possession and attempts to harm his companion in a chilling turn of events.
The following day, Sung-ah crafts a substitute for the human amulet—a whimsical lip balm adorned with eyes, a nose, and lips—ensuring Gyeon-woo's continued protection even in her absence. The manner in which she presents this peculiar talisman to him is nothing short of awkward, painting a humorous yet endearing picture of their evolving relationship amidst the supernatural chaos.
Later that day, Sung-ah can't help but notice a spectral canine trailing after the school bully, and she blurts out, "How adorable." Ji-ho and Gyeon-woo are taken aback, mistaking her words to refer to the bully himself. She swiftly clarifies to Ji-ho, revealing that she was actually commenting on the bully's late dog, which seems to hauntingly shadow him.
Elsewhere, Sung-ah's spiritual mother becomes aware of the dire state of the two men who ventured into the haunted abode and decides to conduct a modest ritual in hopes of retrieving their souls. She summons Sung-ah, who promptly dashes out of school to lend a hand.
Later on, Yeom-hwa pays Gyeon-woo a visit and flings salt at him, labeling him a "newly deceased" and foretelling his impending doom. It transpires that she has been engaged by Gyeon-woo's parents to safeguard themselves from him. Sadly, Gyeon-woo opts to place Sung-ah's talisman in his room rather than keeping it close.
The following day at school, suspicions arise among the students regarding Sung-ah's identity as a shaman, sparked by someone noticing a striking resemblance between her and the shaman captured on camera at the haunted house. Eventually, Gyeon-woo steps in, fury burning in his eyes as Sung-ah fails to assert herself, voicing his deep-seated hatred for shamans.
Meanwhile, Ji-ho confides in Gyeon-woo, sharing how he taught Sung-ah to smile through her pain when they first crossed paths and admitting his crush on her. As this unfolds, Sung-ah and her spiritual mother endeavor to purify the haunted house. On their return journey, they encounter Gyeon-woo, who attempts to peel off Sung-ah's mask, eager to prove to all that she is no shaman.
Later, Sung-ah undergoes a transformation and dashes off to meet Gyeon-woo. As they spend time together, the lights abruptly flicker and plunge them into an eerie darkness, which seems to beckon forth malevolent spirits. During this harrowing instant, haunting flashbacks unfold, revealing Gyeon-woo's history of mistreatment, including Yeom-hwa's cruel act of casting salt upon him. Despite his agony, he had once worn a brave smile. He offers Sung-ah a heartfelt apology for burdening her with his pain, and she responds by embracing him tightly, her warmth seemingly repelling the lurking apparitions.
The following day, Sung-ah and Gyeon-woo share tender, heartwarming moments, their bond deepening. However, Gyeon-woo's resolve to continue with archery earns him a grueling punishment from his coach: he is tasked with running fifty laps between the school and the haunted abode.
Elsewhere, Sung-ah, laden with props for a cleansing ritual, accidentally crosses paths with Yeom-hwa, who is immersed in her own mystical rites. Mistaking Sung-ah for one of General Dongcheon's esteemed shamans, Yeom-hwa summarily removes her mask and urges her to partake in the dance. Meanwhile, as Gyeon-woo arrives at the haunted house, his eyes fall upon Sung-ah, mesmerizingly dancing alongside Yeom-hwa, thereby bringing this eventful chapter to a cliffhanger conclusion.
