If you don't want to know the circumstances surrounding Thursday's entry in this slideshow, then don't read any further...
[spoiler]Thursday's quote:
Ep #490 (1968) - Barnabas - 'And you MUST find some way to get hold of yourself.'
From "#0489/0490: Robservations 05/20/02: If Both Live..."
Barnabas says Julia now knows what it is he discovered years ago--there's no escape from the witch--Julia will have the dream until she's so scared she's forced to tell Mrs. Johnson.Julia insists she must tell Mrs. Johnson before she loses her mind. Barnabas wants them to do the experiment tonight. Find some way to get hold of yourself, urges Barnabas coldly. Julia wonders if Cassandra can somehow control the experiment, but Barn believes she knows nothing about it.
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The Robservations references most of the quote quite well, though not the "must" part...
And this is the second quote from this ep. The first (Mrs. Johnson - 'No, I MUST come in') was back on February 11th.