In the year 1760, the Collins family sets sail from Liverpool to establish a fishing port in Maine, which they name Collinsport. Time passes, and the young Barnabas, portrayed by Johnny Depp, becomes infatuated with his family's maid, Angelique Bouchard, played by Eva Green. However, when Barnabas confesses that he harbors no romantic feelings for her, Angelique retaliates in a shocking manner by murdering his parents. This tragedy leads Barnabas to fall in love with Josette Du Pres, beautifully portrayed by Bella Heathcote.
In a whirlwind of jealousy, Angelique casts a spell that drives Josette to leap to her death from a cliff. Devastated, Barnabas jumps after her, but instead of meeting his own demise, he is transformed into an immortal vampire by Angelique. In a cruel twist, she incites a mob to imprison him in a coffin deep in the woods, cursing his lineage. Fast forward to 1972, and a group of construction workers inadvertently liberates Barnabas from his two-century confinement. Starving after years of imprisonment, he feasts on his rescuer's blood, an act that marks his return to a world he once knew.
Barnabas soon finds his ancestral home populated by a quirky clan of descendants, including the family matriarch, Elizabeth Collins Stoddard, played by Michelle Pfeiffer, her brother Roger, his teenage daughter Carolyn (Chloe Moretz), and several others. They include Dr. Julia Hoffman, a psychiatrist portrayed by Helena Bonham Carter, and the manor's caretaker, Willie Loomis (Jackie Earle Haley). Upon revealing a hidden treasure room to Elizabeth, Barnabas is accepted into the family, but under the condition that he keeps both his vampiric nature and the room's existence a secret.
As Barnabas revitalizes the family’s struggling fishery, he encounters Angelique once more. Now a powerful figure with her own prosperous fishery called Angel Bay, she attempts to reclaim Barnabas’s affections. Despite her charm and hold over him, he resolutely declares his love for Victoria, who he mistakenly believes resembles Josette. Barnabas aims to restore the Collins family name by hosting a grand party, attended by none other than Alice Cooper. During the event, he learns that Victoria, his new governess, has a troubled past; her parents committed her to an asylum for claiming to see Josette's ghost.
Their budding romance infuriates Angelique, who has been watching jealously. Meanwhile, Dr. Hoffman discovers the truth about Barnabas and attempts to exploit him for her gain. In a dark turn of events after realizing her betrayal, Barnabas kills her and hides her body in the sea. As tensions rise within the family, Barnabas confronts Roger about his neglectful parenting, making Roger choose between his son and his freedom. Roger leaves, causing more hurt to young David.
As a series of unfortunate events unfold, Barnabas accidently reveals his identity to the children. This sets Angelique off on a vengeful spree, wherein she traps Barnabas in another coffin and incites the townspeople against the Collins family. With the help of David, Barnabas escapes and confronts Angelique, revealing both their true natures to the mob.
As chaos erupts, Angelique's final act of desperation involves setting fire to the manor, confessing to the havoc she has wreaked on the family—including cursing Carolyn and causing David's mother's death. Barnabas and the Collins family band together to defeat her, culminating in a supernatural encounter with David's mother's ghost, who inadvertently aids in ending Angelique's reign.
In a shocking climax, Barnabas discovers that Angelique has bewitched Victoria into seeking her own death just as Josette did. Racing against time, Barnabas reaches her but is met with a heart-wrenching decision. Victoria desires to embrace the eternal life of a vampire, yet he hesitates, leading to a tragic fall. In a desperate attempt to save her, he bites her, awakening her as his eternal companion. The film closes on a poignant note, with the two sharing a kiss by the tumultuous sea, as deep beneath the waves, the mysterious legacy of Barnabas continues to unfold with the unexpected revival of Dr. Hoffman.
