I love what Willie says about his servitude--and kudos to John Karlen: Maggie asks Willie if he's ever tried to escape. I’ve tried, Willie says sadly, but I never could. I have to drive into town almost every day. Sometimes I’ve tried to just keep on driving, hoping to get a thousand miles away. But Barnabas’s power is too strong to resist, and I’ve been compelled to come back every time. My will isn’t my own, he sighs. I guess I’m doomed.
I'm not so sure that Sarah doesn't notice Maggie. I think, as I said elsewhere, that Sarah is only just beginning to awaken, as it were, so taking a bodily form might have been all she could manage at first. I'll bet the first person she looked for was Barnabas, and she must be incredibly confused and upset at the change in him. We don't know how long she's been watching him, but she probably knows what he's been up to, even if she doesn't understand it. So I don't think it's an accident that our first sight of her is near Maggie's prison cell. And we know that she observes Maggie and Willie's conversation. But after all, she's just a kid in a bewildering situation, so naturally she would revert to the kind of repetitive behavior that provides kids with reassurance--like singing a song or tossing a ball over and over again.
The scene with David and Sarah is really poignant--you can't help feeling sorry for this little girl lost. But she actually speaks directly to another person for the first time, so she's getting stronger.
I still remember how completely stunned I was when I heard Sarah's first words to Maggie at the end of this episode--one of the highlights of the whole series, IMHO.