Dark Shadows - Season 10 Episode 25 DS-1085 Necking in the afternoon.
Overview: Tad and Carrie possess David and Hallie. Julia finds plans by a Quentin Collins in 1840 for a stairway into time. Daphne forces “Tad” and “Carrie” to burn the notebook. Julia searches for the playroom however only finds a closet. Daphne appears to Quentin and gives him a book written by his namesake from 1840. David and Hallie are beckoned by Tad and Carrie to follow them up a staircase.