In the mystical and fog-laden looms of Transylvania, Count Dracula ponders his profound loneliness amidst his winged followers. His solitude is shattered by a phone call from Emma Wishbone, who mistakenly dials him seeking advice on her chaotic life that intertwines the mundane with the supernatural. The conversation falters, and as her phone tumbles into a storm drain, so too does the weight of her growing troubles.
Emma's life is in disarray: the family bookstore faces dire financial challenges, her son Max Wishbone is bullied at school, her daughter Fay Wishbone has fallen into the clutches of self-obsession, and her husband Frank Wishbone has become a mere shadow of himself, consumed by exhaustion. Noticing the opportunity amidst Emma's despair, Dracula persuades the mystical Baba Yaga to grant Emma the curse of immortality.
When Cheyenne, Emma’s contemporary friend, gifts her tickets to a masquerade ball, Emma sees a chance for family bonding through costumes: she dresses as a vampire, Frank as Frankenstein's monster, Fay as a mummy, and Max as a werewolf. However, what begins as a night of excitement soon escalates into chaos as they are mistakenly tossed out of the party by security, pushing Emma into a whirlpool of disappointment.
Seizing upon her vulnerability, Baba Yaga casts a dark spell, accidentally transforming the family into the very monsters they portrayed. As an uproar ensues, Emma embarks on a desperate chase after Baba Yaga, discovering that the sorceress’s amulet must be recharged at the powerful London Eye.
While Max relishes his new monstrous image, using it to turn the tables on his bullies, Fay struggles with heartbreak, and Frank remains supportive yet troubled. Their journey takes a frantic turn at the airport when Fay uses her newfound powers to conjure a plane ticket for their escape.
Onboard, as the stakes rise, Emma grapples with a relentless thirst for blood until Dracula unexpectedly intervenes, whisking her away on his jet and leaving her family stranded. His intention is clear: he is determined to claim Emma as his own.
The flight leads to a confrontation of desires, with Dracula urging Emma to stay by his side. Ultimately, Emma's enduring loyalty to her family triumphs over temptation, prompting Dracula to eject her from the aircraft. She lands beside the London Eye, just as her family arrives, unified in their love for each other.
Unperturbed, Dracula concocts grand schemes of destruction, commanding his servant Renfield to prepare for chaos across the globe. Meanwhile, Baba Yaga's amulet powers surge as she faces the Wishbones, only to redirect them to Egypt when they interfere with her plans. In an unexpected alliance, Cheyenne befriends Baba Yaga during a harrowing rescue.
As the family drifts apart in Egypt, tensions reach a boiling point. Fay captures the attention of Imhotep, Max finds himself feared by hotel guests, and Frank charms supermodels, inadvertently reuniting the siblings at the same venue. Consumed once again by the allure of vampirism, Emma is promptly saved by Dracula but feels a longing for her family's presence.
As fate would have it, the Wishbone family is suddenly transported to Dracula's castle, where Renfield reveals a plan to obliterate humanity with a colossal snowball aimed at the sun. In a strategic twist, the family collaborates to introduce holy water into Dracula’s pool of Lazarus, deepening his defeat.
Realizing that their collective happiness is essential to breaking the curse, the family regains their human forms. With assistance from Renfield and the ill-fated bats, they ensnare Dracula in sunlight before using his own weather weapon against him.
Upon returning home, life takes a significant turn for the Wishbones: Frank gains the confidence to advocate for himself, Max's previous bully seeks friendship, and Fay finds romance at a home-hosted costume gathering. As the joyous celebration unfolds, Baba Yaga, Renfield, and the bats join the festivities, culminating in a family photo that captures their renewed joy and unity.
