If you don't want to know the circumstances surrounding Wednesday's entry in this slideshow, then don't read any further...
[spoiler]Wednesday's quote:
Ep #475 (1968) - Dr. Lang - 'Oh, yes, I suppose I MUST.'
From "#0475/0476: Robservations 05/09/02: Give Me Jeff Clark's Face!"
Barnabas tells Lang his visitor was Angelique--she turned Ben mute and tried to give him a similar attack. Lang agrees he must accept this
[/spoiler]
The Robservations references the quote fairly well. However, before Dr. Lang delivers the quote and after Barnabas explains about Ben and says surely Lang believes him now, Lang replies that he doesn't want to believe him. It's only after Barnabas says Lang must that Lang delivers the quote...
And this is the second quote from this ep. The first (Dr. Lang - 'No! No! No one else MUST know!') was back on October 16th of 2020.