Grace's will is of the negative female variety - she can deny and reject much more easily than she can affirm or accept. Somewhere within herself - he's seen it, if only for a moment, that conscious, even cunning look in the corner of her eye - she know she's concealing something from him. As she stitches away at her sewing, outwardly calm as a marble Madonna, she is all the while exerting her passive stubborn strength against him. A prison does not only lock its inmates inside, it keeps all others out. Her strongest prison is one of her own construction.