Martha: Alexis' moving out got me to thinking. And after many hours of soul searching, I have made a decision.
Castle: Have you now?
Martha: Yes. I have decided, out of the goodness of my heart, that I will continue to live here...
Martha: Please don't interrupt. I will continue to live here so that you, Richard, will never, ever be alone.
Castle: You'd do that for me, mother?
Martha: It's a parent's sacrifice.