Irene Dunne stars as a musical hall entertainer who is impregnated by a wealthy young man (Phillips Holmes). They marry, but the husband kills himself. Under the pressure of father-in-law Lionel Atwill, Dunne gives up the baby. Two decades pass: Irene crosses her son' path again. He commits a murder, and she willingly takes the blame--never letting the boy know her true identity. Secret of Madame Blanche is a remake of an equally teary Norma Talmadge silent film; both pictures bore the heavy influence of Madame X.