The movie wasn't really derived from Dark Shadows - they developed a whole new script for that particular one.

Long after the series was cancelled and while co-starring opposite his old friend Jane Alexander in the short-lived series Tell Me You Love Me Selby was grief-stricken when his series' lead and friend Jane Wyman died in 2007. He eventually brought his Dark Shadows character to film with the second Dark Shadows movie Night of Dark Shadows released in 1971 after the TV series' cancellation. He played Abraham Lincoln in the Touched by an Angel episode "Beautiful Dreamer".

The naturally black-headed Selby is best known for playing the roles of Quentin Collins on the ABC-TV serial Dark Shadows (a role he played from 1968 to its ending in 1971 and again in the recent audio revival) and as the evil and compassionate estranged son of Angela Channing (played by Jane Wyman) Richard Channing on the primetime CBS soap opera Falcon Crest (a role he played from 1982 to 1990). He has worked in movies soap operas and television.