At the end of the play, Mrs. Alving clutches morphine and looks at her withered son as a ruthless, revelatory sun spills over the scene. An articulate woman, she ends the play screaming monosyllables: "No. no; no!--Yes!--No; no!," and tearing her hair. Her life of calm, reasoned arguments is over. Her son Oswald has demanded action – he wants her to help him kill himself.
Just before his final meltdown, Oswald argues to his mother that common genes don't necessarily lead to love. It's a hard lesson for his mother to learn. He doesn't love her, but sees how she can be useful. Oswald asks her to take back the life she gave him: "I never asked you for life. And what sort of a life have you given me? I will not have it! You shall take it back again!" (3.245). The mother-child bond is the last ghost Mrs. Alving may have to give up.
What does she do? Ibsen doesn't tell us. If you were a director making that decision, what does it mean for the play? Will Mrs. Alving accept her solitude (think about it, she's all alone in that big, dark house) and kill her son? Is Oswald another "ghost" she has to get rid of? Will she keep him, nourishing an image of herself as a caregiver? What happens next? It's quite a cliffhanger and we have to fill in the missing pieces.