At La Casa di Sol, an ancient Venezian home once beloved by a stream of composers, a young violinist practices a piece by Paganini and then inexplicably electrocutes her bathing mother with a hairdryer. In the present, a female rock band is recording in a studio, and their manager, Lavinia, urges them to find a fresh song. The drummer, Daniel, travels to meet a shady figure, Mr. Pickett, who sells him an unpublished Paganini score. Daniel demonstrates the new piece—titled “Paganini Horror”—to Lavinia and the band’s lead singer, Kate, and all three agree to record it. Lavinia suggests hiring the famed horror director Mark Singer to shoot a video, and Kate suggests filming at La Casa di Sol, where Lavinia also reveals she knows the house’s current resident, Sylvia Hackett.
During the preparations, Sylvia recounts a chilling legend: Paganini himself once lived there and murdered his bride in the house. Meanwhile, Mr. Pickett makes a fateful trip to St Mark’s Campanile, where he tosses Daniel’s money from the roof and invokes Paganini’s curse. As the story moves from superstition to danger, the band members begin to fall victim to the house’s malevolent influence. Rita, the bass player, encounters the figure of Paganini, whom she mistakes for Daniel in costume, and he stabs her to death with a violin. Sylvia and the guitarist, Elena, announce Rita’s disappearance, and Lavinia suggests replacing her while Mark contemplates finishing the video with mannequins as stand-ins.
Daniel’s fate darkens quickly: he sees Rita’s ghostly presence and is drawn to another room where Paganini murders him. The group’s fear intensifies as the ground beneath Kate opens up, and while Mark tries to pull her free, he is electrocuted and Kate is dragged into the pit. Lavinia and Elena escape the hall only to witness an invisible barrier slam shut, flinging Elena from a car and consuming the vehicle as flames rise around Mark. Lavinia discovers a tunnel beneath the hole and descends in a desperate bid to locate Kate, while Elena and Sylvia hear Lavinia’s scream, though Elena suspects the sound comes from upstairs, prompting a cautious investigation.
Sylvia’s evening grows increasingly surreal as she follows ghostly violin music toward the courtyard, where she briefly encounters Daniel—who then vanishes as Kate reappears in the empty courtyard pool. The two of them resolve to find the others and escape the nightmare. Lavinia returns from the hole and reunites with the others, only to find Elena missing and a trail of blood leading them upstairs. They find Elena dying, her body marked with a strange fungus once associated with the wood used to craft Stradivarius violins; Lavinia explains that the fungus hints at a historic link to the violins’ lore.
Kate proposes using Paganini’s own piece as a weapon to break the curse, and she begins to play it on her violin. Yet the escape route remains blocked by the same invisible barrier. Desperation turns to counterstrike when Kate tries to reverse the magic by playing the piece backward, but the attempt sears Lavinia with an electric spark and traps her behind the barrier where she is crushed. Paganini materializes, stabbing Sylvia with his violin and sealing Kate inside an empty double bass case. As Paganini plays, Kate awakens inside the case, which catches fire, while the sun finally breaks through the window, reducing Paganini to dust and incinerating the sheet music.
Kate makes her exit as Sylvia, believed to be dead, arrives by car and reveals a grim truth: because Kate never played the piece backward, Paganini’s curse will continue to ensnare new visitors. Pickett steps out of the car, and Sylvia confesses a terrible family secret—that she murdered her own mother in the house when she was a child and has been condemned to relive the haunting ordeal for eternity. Pickett adds that all visitors to the house are condemned to Hell, and the cycle seems ready to begin anew when a new family arrives. As Kate appears poised for freedom, Pickett reveals his hatred for those who sell their souls for fame and ends her life with a final, fatal stab.
In the end, the house remains a trap for the curious and ambitious, a place where music, legend, and a centuries-old curse intertwine, and where the price of ambition is paid in lives that echo through the halls of La Casa di Sol.
