I like the possibilities that lie open in this episode.
First, we've got the possibility that Barnabas's personality will be transferred to Jeff Clark's body, with the result that Roger Davis will be playing Barnabas. We've got Vicky interested in Jeff because he's been displaying signs of being Peter Bradford without knowing it. Will Vicky remain interested in Jeff if he is possessed - so to speak - by Barnabas? Will Barnabas be smart enough to throw in the occasional reference to 1795 to keep Vicky thinking that he's Peter Bradford? And will Jeff Clark start wearing spiky bangs?
Next we've got the possibility that Angelique will possess Roger, with the result that Louis Edmonds will be playing Angelique. Will Angelique go the cannery every day as Roger did? Will she recognize Barnabas in Jeff Clark's body and, while still in Roger's body, start making moves on Jeff/Barnabas? Will we get to hear Louis Edmonds doing an Angelique-style laugh?
And what sort of trouble will Harry Johnson get himself into?