Salvation Joan is a society girl who wearies of the empty life of society when she realizes the suffering, misery and poverty that exists in the great city in which she lives, in spite of the apposition of friends and relatives she joins the Salvation Army, but conceals her identity. Joan is attracted by Bill, who she thinks, is one of a gang of rough characters of the saloon and gambling places, but who really has more sterling qualities of manhood concealed within him if they could be brought out. In a fight started at a Salvation Army meeting by the rowdies, Bill comes to the rescue of Salvation Joan, in spite of the risk of great danger to himself. This wins the gratitude of Salvation Joan and the result is that Bill becomes a regular attendant at the Salvation Army services. It is hard to keep love and religion from mixing. As a society girl Salvation Joan had previously broken off her engagement to Phillip Balston because somehow she could not place confidence in him. This distrust was well borne out when Ralston's associations with gangsters was accidentally revealed to her one day when she chanced to discover him leaving a meeting with a crowd of them. To promote his sinister ends, Ralston traps Madeline Ellison, sister of Joan and the wife of Ambassador Ellison, and threatens that if they expose him he would scandalize Madeline. The situation becomes more and more complicated and reaches its final climax when "Bill," after an evening of thrilling adventures, turns out to be a secret service man and arrests Ralston as a spy, saving the country from war. Ralston, in an attempt to escape, is shot and killed. "Bill's" heroism wins the heart of Salvation Joan, and both reveal their identity and vow that they love each other.