What Karen wants to do - needs to do - is cry, but she can't. Here, alone, when she could howl, beat the sofa cushions, scream; now, somehow, she is unable. It's for fear that if she gives in to it, she'll lose all sense of who she is. She is afraid that if she falls apart in private, then she'll fall apart completely. That if she crumbles, like a house in an earthquake, she will disappear down some deep, dark crevasse, and never be able to pull herself out and put herself back together again.