The theme of "A Temporary Matter" is to show how deception, grief, and alienation destroy a marriage.

As the story opens, Shukumar and Shoba are dealing with the bitter disappointment of losing their first child. They avoid each other and barely speak. Shukumar displays his grief by lying in bed and not working on his dissertation as he should be. Shoba has become careless about the house and no longer cooks.

During the course of a few evenings when the power is shut off, they seem to come back together as they light candles and talk over dinner and wine. They begin a ritual of telling each other ways they deceived the other person in the past. These are mostly minor things, and Shukumar, the point-of-view character, hopes the marriage is healing. He is especially hopeful after he and Shoba make love.

But Shukumar is ignoring that their interactions show that their marriage has a history of small secrets and deception. They have had a marriage based on deceptions, and he is deceiving himself about the future he imagines they will have together. He finds that he misinterpreted Shoba's sharing of deceptions as a form of rebirth—she had all the time been looking for and found another apartment. She had been ending the relationship their last few days together, not renewing it.

The story shows that a marriage can fall apart when too much deception, alienation, and grief enters into it and that the wishful thinking of one partner can't save it.

What is a major idea that comes out of the themes of "A Temporary Matter?"

I think that one of the significant ideas that comes out of Lahiri's short story is that there is a level of emotional duplicity that is present in relationships.  There is nothing to suggest that Shukumar and Shoba's relationship is ladened with secrets or is predisposed to secrets of deception.  Their relationship is standard.  Yet, the entire game that they play during the power outage is reflective of how much both have kept from one another.  The transgressions are small, to an extent.  Yet, as the game increases in duration, worse elements of deception are revealed and the entire relationship turns in a brutal game of disclosure.  This becomes one of the major ideas that comes out of the story.  The most basic of relationships can contain the most brutal of secrets.  When Shukumar tells Shoba of his secret, it is a reminder of how two people who are not malevolent or evil by any means can display the worst of cruelty to one another.  This deception becomes one of the major ideas of the story, one that reflects how relatively good people can do some terrible things in the name of love of another.