Dark Shadows - Season 7 Episode 20 DS-720 Necking in the afternoon.
Overview: Quentin warns Barnabas to not get any ideas about killing him; Barnabas warns Quentin not to trust Angelique. Quentin is surprised to see Jenny, his wife. Dirk finds Quentin stabbed to death; later Barnabas finds Dirk standing over Quentin’s body.