Told in flashback, Affair with a Stranger recounts the deteriorating marriage of playwright Victor Mature and model Jean Simmons. The union is strained by the death of Jean's baby and the pressure of Victor's career. A scheming actress (Monica Lewis) makes a play for Mature, leading Jean to file for divorce. The couple is brought back together by the adoption of a baby (the "stranger" of the title). Affair with a Stranger is unabashed soap opera, made plausible by the sensitive performance of Jean Simmons.