Clara Kimball Young portrays two roles. As Janet, a convent novitiate, she agrees to exchange places with her sister, Lucy, a cabaret dancer, who believes she has killed a man.
After leaving a wealthy Belgian family to become a nun, Sister Luke struggles with her devotion to her vows during crisis, disappointment, and World War II.
A group of travelers are forced to seek shelter inside an abandoned jail where a notorious nun named Sister Monday had once been assigned and was suspected of murdering prisoners.