And additionally the script explains that -
Barnabas turns, anguished, as Sarah dissipates, drifting into the darkness like dust. Conflicted, he turns back toward the mansion, where Victoria remains framed on the balcony.- right before today's quote -
Page 37 - Barnabas: 'I can't...'
- and the scene concludes with:
As camera CRANES UP, Barnabas reaches toward the sky, his torment etched across his face...FADE OUT
END OF ACT TWO
And it's interesting how in some ways this scene is quite similar to one in the pilot for the '91 series. In that scene Vicki is in her room and brushing her hair before she turns down her bed and goes to the window. Outside, Barnabas watches and bares his fangs. But then he is startled by a child's voice calling "Barnabas... Barnabas..." He turns to look in all directions, finally spotting the figure of a girl. Astounded, he calls out "Sarah, is that you?" to which Sarah begs "You must stop, Barnabas... You must stop..." Elated by the sight of her, he begins walking toward her saying "You've come back" - however, she turns and runs from him - which prompts Barnabas to frantically run after her shouting "No! Sarah! Wait! Don't leave me! Sarah! No, Sarah! Please don't go away!" But sadly for him the child has completely vanished, and that prompts him to weepingly say "Sarah... Sarah... My sweet little sister... Come back!" He collapses to his knees and with anguished sobs pleads "Please don't hate me... Please! I cannot help myself!!" And that ends that pilot - though it was never scripted to end that pilot - but that's an entirely different story for an entirely different topic...
One thing that's quite fascinating about the way the scene is scripted for this pilot, aside from the potentially interesting special effect of Sarah dissolving, is that in this pilot the audience never does learn that Sarah is Barnabas' sister. Apparently that was being held as a big reveal for some future ep...