Max, portrayed by Anton Yelchin, is a passionate horror enthusiast with a romantic heart who becomes deeply entangled in a whirlwind of emotions while trying to navigate his complex relationship with the alluring Evelyn, played by Ashley Greene. An ardent environmentalist, Evelyn is zealously committed to sustainability, while Max dreams of opening a horror memorabilia shop. To maintain harmony in their relationship, he begins sacrificing his own aspirations and lifestyle choices, including his cherished car, in an effort to keep Evelyn content.
Yet, hidden beneath the surface is Max's profound desire to establish his own horror haven, a venture that Evelyn views with skepticism and disinterest. One night, while unloading new inventory at his workplace, Max discovers a baffling artifact known as the Satan Genie, rumored to fulfill anyone's deepest desires. Initially regarding it as a mere novelty, he later stows it away in the shop's storage, unaware of the chaos that looms ahead.
As they bask in a moment of genuine intimacy, the couple takes a significant step in their relationship when Evelyn moves into Max's apartment. They celebrate this milestone with a horror-themed ice cream treat from Olivia's quaint shop, portrayed by Alexandra Daddario. However, tensions rise as Evelyn harbors a palpable animosity towards Olivia, driven by her misinterpretations of the situation.
In a heart-wrenching moment, Evelyn confides in Max that he is the only source of joy in her life since the passing of her mother, an admission that carries substantial weight in their relationship. However, idealism starts to unravel when Max returns home to find their apartment dramatically altered, as Evelyn’s personal tastes have replaced the shared memories and collectibles that once filled their space. This triggers a clash over control, making Max question whether he can endure life suffocated by Evelyn’s domineering preferences.
Max turns to his laid-back half-brother Travis, played by Oliver Cooper, whose offbeat advice leads him to consider a public breakup. But fate takes a dire turn when Evelyn’s abrupt exit to the park results in her being struck by a bus, leaving Max devastated and grappling with the implications of their strained relationship.
In the aftermath of her tragic passing, Max's emotional state spirals into despair. However, with Travis’s gentle nudging, he gradually re-enters society, and a chance meeting with Olivia ushers in new possibilities. Their mutual fascination with horror flourishes, and after a poignant night spent sharing chilling tales, a shocking discovery unfolds: Evelyn has miraculously returned from the dead, her eyes shining with an eerie brightness. The joyful reunion is clouded by her delusion that their relationship remains untouched, forcing Max into a harrowing situation as he balances feelings for Olivia and the haunting specter of Evelyn.
As Max delves into desperate attempts to resolve his predicament, he learns that the Satan Genie's remains are shattered, leaving him adrift in his quest to find closure. Unfazed, he turns to the occult, only to find that meddling with life and death is an unpredictable affair fraught with peril. As Max navigates this tumultuous emotional landscape, Travis stumbles upon a shocking reunion with the now-inebriated Evelyn, imposing a grotesque ultimatum for Max.
With Halloween approaching, events take a bloody turn as Travis, unknowingly drained by Evelyn’s insatiable hunger for human flesh, falls victim to her cravings. Meanwhile, Max and Olivia’s bond strengthens amid escalating chaos. A tumultuous confrontation at Max's apartment culminates in a violent showdown with the reanimated Evelyn that reveals Travis as another unwelcome zombie. Ultimately, his sibling’s deadly intervention ends Evelyn's reign of terror, allowing Max and Olivia to mourn their losses and tentatively rebuild their lives together.
As the new year dawns, Max and Olivia's connection blossoms into a business partnership, integrating Max's passion for horror with Olivia's sweet treats, bringing him newfound joy. In a heartfelt culmination, he proposes to Olivia, who joyously accepts, solidifying their love and future together. Intriguingly, even as they embark on this new venture, the undead Travis continues to linger on the periphery, spinning a sign outside the shop, adding a whimsical yet eerie touch to their journey ahead.
