Whitney Cameron is in a quandary: he's attracted to his beautiful sister-in-law, Lynn, but also harbors serious suspicions about her. Her husband, Cameron's brother, died under mysterious circumstances, and now that the death of her stepchild, Polly, has been attributed to poisoning, he suspects that Lynn is after his late brother's estate, and killing everyone in her way.

Connie is a widow and mother whose work involves checking up on the competition for her department store employer. When Steve, a charming salesman at a competing store, recognizes her true motives but refuses to expose her, he ends up getting fired as a result. Feeling guilty, Connie agrees to buy lunch for Steve, striking up a friendship that complicates her relationship with Carl, a lawyer who wants to marry her.