Ultimately, each character is isolated from the other at opposite ends of the staircase. In order for the marriage to succeed, each character must travel an equal distance up or down the staircase in order to meet the other. The husband attempts to empathize with his wife, moving up the staircase toward her and essentially moving backward in his own journey towards acceptance of his child’s death. Even so, the wife is unable to empathize with her husband and only moves down the staircase after he has already left his position at the foot.
I'd like to get away from earth awhile
And then come back to it and begin over.
May no fate willfully misunderstand me
And half grant what I wish and snatch me away
Not to return. Earth's the right place for love:
I don't know where it's likely to go better.
I'd like to go by climbing a birch tree,
And climb black branches up a snow-white trunk
Toward heaven, till the tree could bear no more,
But dipped its top and set me down again.
That would be good both going and coming back.
One could do worse than be a swinger of birches.