Much like in the series, Julia is the live-in psychiatrist of the Collins family, and she was hired to tend to young David Collins, who had been seeing the ghost of his mother (who was killed by Angelique). She later began performing her same duties with Barnabas Collins, though it was through hypnosis that Julia learned that Barnabas was a vampire, causing her to go into a panic while confronting Elizabeth about her knowledge of her ancestor's true identity. Julia informed Barnabas that she wanted to cure him of his vampirism, with the plan involving experimental blood transfusions. She stated that she was taking his blood as part of a test, though later on, Julia begins acting oddly and wants the curtains closed to be away fron the sunlight.
As her demand indicated, Julia's seemingly helpful nature was a mask for her true persona as a self-serving villainess. Barnabas was left believing that Julia was helping cure him, but in actuality, the evil Julia used Barnabas' blood for her own purpose: to remain young and live as a vampire. All the while, Barnabas went to Julia's lab for another session due to the fact that he had fallen in love with Victoria, and it was there that Julia's heel turn took place, as she was caught inserting the vampire blood inside of her. The villainess voiced her fear and insecurities over getting older, using that as her motive for her deceptive actions. An angry Barnabas responded to Julia's actions by biting her throat and taking back his blood while draining hers. While she was being drained, Julia had flashed a pair of fangs, revealing that she had become a vampiress.
Julia's body was dumped into the water by Barnabas and Willie Loomis; however, the very final scene of the film showed Julia's eyes opening, revealing that she is immortal and alive as a vampiress.
- The 2012 Dark Shadows film is the only incarnation to cast Dr. Julia Hoffman as a villainess.
- Helena Bonham Carter is perhaps most famous for portraying the evil Bellatrix Lestrange from the Harry Potter series. She also played psychotic villainess Mrs. Lovett in Sweeney Todd: The Demon Barber of Fleet Street and The Red Queen from Alice in Wonderland.