In The Way Up To Heaven, the story changes when Mrs. Forster undergoes a mental and emotional transformation.
The metamorphosis from long-suffering wife to confident matriarch is supported by Roald Dahl's eloquent diction. In the beginning of the story, Mrs. Forster is described as a woman who has a 'pathological fear' of being late. Her husband is clearly the more level-headed of the two; however, he isn't a very likable character.
...his timing was so accurate - just a minute or two late, you understand - and his manner so bland that it was hard to believe he wasn’t purposely inflicting a nasty private little torture of his own on the unhappy lady. He must also have known that if he was prepared to wait even beyond the last moment of safety, he could drive her nearly into hysterics.
Mrs. Forster is further described as a woman who 'was and always had been a good and loving wife,' a companion who had served her husband 'loyally and well.' The phrase 'was and always' is characteristic of Mrs. Forster's personal ethics as a married woman; here is a woman whose husband's needs have always superseded her own. Therefore, the change in temperament is further heightened by Dahl's use of foreshadowing:
She looked at him, and at that moment he seemed to be standing a long way off from her, beyond some borderline. He was suddenly so small and far away that she couldn’t be sure what he was doing, or what he was thinking, or even what he was.
This foreshadowing highlights the initial shift in Mrs. Forster's focus, a crucial turning point where Mr. Forster ceases to have any direct influence on his wife's emotional equilibrium. When Mr. Forster goes off to search for his daughter's gift, Mrs. Forster's transformation continues. Her frantic agitation gives way to cool deliberation. Consider the descriptions Dahl uses:
...she stood there absolutely motionless,...
...Her whole attitude was a listening one...
...to hear and to analyze these sounds that were coming faintly from this place deep within the house.
...the whole expression had suddenly altered. There was no longer that rather soft and silly look. A peculiar hardness had settled itself upon the features. The little mouth, usually so flabby, was now tight and thin, the eyes were bright, and the voice, when she spoke, carried a new note of authority.
As I mentioned earlier, this change in Mrs. Forster's attitude signals a mental and emotional transformation. Subsequently, the mood of the story also changes, from one of pity (and perhaps even outrage for the treatment Mrs. Forster endures) to one of anticipation ( will Mrs. Forster overcome her circumstances in life?) At last, when the story ends, we are left contemplating Mrs. Forster's cold, calculative decision: she knew that her husband was going to die in the malfunctioned lift without further intervention; yet, she left him to his fate. A fantastic ending which leaves us wondering whether Mrs. Forster has been merely clever, or is guilty of murder, a subject for another day.
Hope this helps!