He was the star of NoDS (Night of Dark Shadows) and played a dual role--Quentin Collins, who inherits the house in the present (1971), and Charles Collins, an adulterous painter who lives ca. 1810 and whose affair with the mysterious Angelique is the seed of the whole story.
I do vastly prefer Night of Dark Shadows of the two films. If Darren is ever successful in his efforts to restore the missing footage, the story will actually make sense, and maybe others will realize what an unusual gem it really is. As Grayson pointed out long ago in an interview, there was something really special there before the studio forced them to hack it to bits and pieces.
Gothick