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.