It is evening in the library of Lady Britomart Undershaft's house in January 1906. Her son, Stephen enters. Britomart aggressively announces that as a grown man, Stephen must take charge of the family affairs. Lomax, his sister Sarah's fiancé, will not receive his trust fund for years. Barbara, the most promising member of the household, has joined the Salvation Army and taken up with a tempestuous Greek scholar, Adolphus Cusins. Britomart cannot avoid the topic any longerthey must speak of Stephen's father, the great military industrialist Andrew Undershaft.