Julia Hoffman first got involved with the Collins family when investigating the supernatural happenings at Collinwood. Unlike the local residents, Dr. Hoffman quickly discovered that Barnabas Collins was a vampire. Only instead of killing him, she became fascinated by her discovery and convinced Barnabas she could find a cure for his vampirism.
Julia’s alliance with Barnabas started out shaky (he nearly killed her several times), but eventually the two came to trust one another. Julia remained Barnabas’ closest ally, with hints of an even deeper connection, as she worked beside him to protect the Collins family.
The character of Dr. Julia Hoffman was originally written as a man; Dr. Julius Hoffman. The writers decided suddenly to change it.