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 #250 (1967) - Barnabas - 'Now you know what you MUST do just before the sun sets, don't you?'
From "#0249/0250: Robservations 11/16/01: Maggie Fakes It"
Maggie follows the sounds of the hammering (Willie has built the coffin for her vampire self) and eavesdrops on Barnabas and Willie down in the basement. Barnabas explains that his power over Maggie isn't absolute, but once she becomes as he is, he will have none--she will be his, forever, Josette, and never remember Maggie. Barnabas comments that he's sure Josette will love the coffin, but Maggie, hugging a brick wall, listening to all this, doesn't look anything but petrified.
The Robservations, being another with very little detail, doesn't reference the quote at all. However, the quote comes up before Willie says he knows he's to bring her the gown she's supposed to wear and then he's to bring her down there, and before Barnabas explains about his power over Maggie...
It's funny how in these early Old House eps people get to the basement after going through the doors in the drawing room between the windows and the fireplace, but that's completely forgotten about in future eps and there's a steel door in the foyer that leads to the basement. And we can't even try to explain it away by saying maybe Willie eventually installed a more direct route to the basement while he was fixing up the house because the steel door is used in 1795/96.
And this is the second quote from this ep. The first (Maggie - 'My name. My name. I MUST remember my name') was back on November 3rd.