Nicholas Blair arrives at Collinwood, claiming to be Cassandra's brother.

Synopsis

A night of horror at Collinwood, for a woman who came to the great house two hundred years ago as a witch has come again and has placed a spell so that the mistress of the house imagines that she lives in the year 1795, and the agony of it, as always, is on the people who love her.

Roger is very worried about Elizabeth, and expresses his fears to Barnabas, who attempts to comfort him. Roger tells Barnabas about the family legend of the tower room, in which someone was locked away, and was surprised that Barnabas found Elizabeth there. He explains it away as intuition.

Julia informs them that although the poison is an old, herbal poison, Elizabeth will survive her suicide attempt. She is still worried about Elizabeth's mental health and advises Roger to send her to Windcliff.

Professor Stokes continues to tutor Adam, whose reading and speech have greatly improved.

Nicholas Blair arrives at Collinwood, claiming to be Cassandra's brother.

Memorable quotes

Prof. Stokes: "L" is not a letter I care very much for.

Dramatis personae

• Jonathan Frid as Barnabas Collins
• Louis Edmonds as Roger Collins
• Grayson Hall as Julia Hoffman
• Robert Rodan as Adam
• Thayer David as Timothy Eliot Stokes (uncredited)
• Humbert Allen Astredo as Nicholas Blair (uncredited)

Background information and notes

Production

• This episode was recorded out of broadcast sequence. The previous episode to be recorded was 525.
• First appearance of actor Humbert Allen Astredo and the character Nicholas Blair.
• Thayer David and Humbert Allen Astredo are accidentally uncredited.

Story

• Julia says that Stokes's phone number is ROckport 6868. (By the mid-1960s, many areas of the country had switched to all numeric phone numbers, but many areas, mostly rural, were still using named exchanges. However, since the mid-1950s, all such exchanges consisted of a name and a number, such as ROckport-5. A phone number ROckport 6868 would not be possible after the mid 1950s and was probably used so that viewers could not try to call Prof. Stokes). [By this time, the 60s, 7 digit phone numbers were pretty much universal in the USA. It was still common to use the name exchanges simply out of habit.] In episode 550, Stokes' telephone dial bears a label reading "COLLINSPORT 4099." [In other episodes, 4099 is the number of Collinwood.] [She doesn't really say that the number is ROckport-6868. She says, "It's Rockport, but you can dial it. It's 6868," meaning he can dial the number directly even though his house is in Rockport, not Collinsport; that is, he doesn't need to call the operator to place the call. When Barnabas dials the number, he clearly dials only 6868.]
• Prof. Stokes's apartment number is 13.
• INTERNAL MONOLOGUE: Barnabas: Angelique's portrait.
• TIMELINE: Cassandra hasn't been seen for over 24 hours, (she disappeared in 519). Roger first noticed signs of Elizabeth's strange behavior three or four days ago, (she began her fear of death in 513).

Bloopers and continuity errors

• During the teaser, there is an odd zoom out and focus on the portrait of Barnabas while dialogue between Roger and Barnabas goes on off screen. It lingers there for quite a while. [Addendum: This seems to be some kind of reminder of Barnabas being the same Barnabas of 1795 as Roger talks about Naomi. It is done a bit inelegantly, though. On the other hand, Jonathan Frid and Louis Edmonds seem to be having significant trouble with their lines during this scene, so perhaps something was going on with them that required they not be seen.]
• In Act II, when Stokes sits down on the couch, a person’s shadow can be seen moving by the door.
• After Roger goes to see if Cassandra is at the door and Barnabas and Julia walk in, a stagehand's hand can be seen opening the main outside door as Roger, Julia, and Barnabas talk in the entry to the drawing room. [Opening the door doesn't make sense as the next time we see the door is when Nicholas arrives and it is closed]
• After Prof. Stokes takes a drink of his sherry, he coughs.
• After Barnabas says he'll go upstairs to say good night to Liz but really intends to search Cassandra's room, he stays near the front door. Yet an instant later he is upstairs in Cassandra's room without ever having climbed the stairs. [The blooper is that we see Jonathan Frid not going up the stairs. He turns from the stairs and waits because he needs to get to the next set. One possibility is that we could say Barnabas is stopping to take off his coat, as when we see him in Cassandra's room, he is no longer wearing his coat. However, based on the appearance of Frid's movements, it seems the script is suggesting Barnabas is indeed going upstairs. Regardless, there is pleny of time between when we see him leave the drawing room and then in Cassandra's room for him to have reached it as there is time spent on-screen with Julia and Roger talking.] Also, when Barnabas asks if Elizabeth is asleep, Roger nods his head yes, but then Barnabas says he'll go upstairs to say hello.
• A stagehand can be seen walking near the chair as the end credits begin.

External Links 

Dark Shadows - Episode 521 on the IMDb

Dark Shadows Every Day - Episode 521 - Look Who's Talking

The Dark Shadows Daybook - Episode 521

Dark Shadows Commentary- Episode 521: All the words

Dark Shadows Before I Die- Episode 521: 6/25/68