Eileen marries Richard from a wealthy corporate clan, only to discover her cold, power-hungry mother-in-law Margaret secretly brews tonics laced with sedatives and nerve suppressants. Margaret plans to cripple Eileen’s judgment to seize her family shares via a pre-nuptial clause. Pretending constant drowsiness, Eileen secretly collects drug samples and gathers all hidden evidence. She gradually swaps Margaret’s toxic soup with harmless substitutes, letting the old matriarch suffer identical mental fog and memory lapses. After a long silent standoff, they confront each other. Instead of ruthless retaliation, Eileen chooses reconciliation. Margaret abandons her schemes, confronts her lifelong regrets, and the two learn to live side by side without manipulation.
