The play begins when the estranged wife of Andrew Undershaft, Lady Britomart, calls Stephen, her son, in for a conference. Lady Britomart is so domineering and Stephen is so intimidated that he is virtually speechless. She immediately corrects his behavior and reminds him that he is now twenty-four years old and thus a grown man, and that he has traveled throughout most of the world; therefore, it is now time that he take over some of the responsibilities of conducting the family's business affairs. Stephen becomes increasingly more intimidated by his mother and maintains that he has deliberately avoided entering into the family's affairs. Stephen, out of respect for his mother's feelings, has been especially reluctant to mention his father's name; Stephen's father, however, is exactly the topic that Lady Britomart wants to discuss. She says, "We can't go on all our lives not mentioning him." She then begins to lay out the problems facing them and the necessity for talking about Stephen's father, Andrew Undershaft, the fabulously wealthy munitions manufacturer who has not seen any of his family since the children were very small.
As Lady Britomart outlines the "family problem," we learn that Stephen's two sisters are planning on marriage. Sarah Undershaft has made a good match, but her fiancé cannot come into his millions until he is thirty-five years old. In the meantime, the couple will have to have more than his present eight-hundred-a-year allowance in order to live in the manner to which they are accustomed. Even worse, Barbara Undershaft, who showed such promise of making a brilliant match, has, instead, joined the Salvation Army, and she spends her evenings with a "professor of Greek," whom, according to Lady Britomart, Barbara "picked up in the street" and who pretends to be a Salvationist and plays the big Army drum for Barbara in public because he has "fallen head over ears in love with her." Lady Britomart, however, maintains — indeed, she insists — that she herself is not a snob; therefore, a professor of Greek will make a respectable and presentable husband because no one objects to classical Greek, but this pair will also need money because professors are notoriously as "poor as church mice." And, furthermore, it is a known "fact," according to Lady Britomart, that refined, poetic people like Adolphus Cusins need more money than other people do because they are too esoteric to understand money; thus, they will need a large sum of money for their marriage. Finally, Lady Britomart tells Stephen that she expects him to get married soon; he has been a bachelor long enough.
With the above explanations and with the knowledge that Lady Britomart's father, the Earl of Stevenage, needs all of his resources to keep up his position in society, she wonders: Where is the money to come from? She then points out to Stephen that because there is always a war going on somewhere, Stephen's father surely must be fabulously wealthy. Stephen agrees and points out how well known the Undershaft name is and how he has been the victim of many unpleasant comments because his name is associated with the "blood and destruction" of the Undershaft munitions. In fact, they both agree, the firm of Undershaft and Lazarus controls most of the munitions of Europe (if not of most of the world), and it is beyond the arm of the law; thus, Andrew has used his power to establish his own eccentric concepts of morals and ethics. Here, it is important to note that Lady Britomart explains that she left Andrew Undershaft because he became head of the Undershaft corporations for one reason only — because he was not a legal heir: He was illegitimate, a foundling — and it has been a centuries-old tradition to leave the business to another foundling. Therefore, Lady Britomart became highly indignant when Andrew insisted that he would leave his wealth to another foundling rather than to his natural son, Stephen. Furthermore, while Andrew has lived a perfectly moral life himself, he has nevertheless advocated things that his wife considers immoral: "So I couldn't forgive Andrew for preaching immorality while he practiced morality." Therefore, she left Andrew to protect the children from his outrageous and unconventional morals and opinions. However, they have always been dependent on him financially, and even though Stephen is naively shocked to hear his mother speak so boldly, Lady Britomart points out that she has asked Undershaft to come here this very evening to discuss the financial arrangements which will be necessary for the marriages. Thus, Undershaft is due to arrive any minute. This impending appearance, as might be expected, causes further dismay for Stephen.
This first scene conventionally and economically sets up some of the main conflicts in the drama; that is, we learn who is to inherit the munitions factory and the facts about Andrew Undershaft's immense wealth. In traditional dramatic terms, this scene would be called "the exposition scene"; Shaw's technique is influenced by the famous Norwegian dramatist Henrik Ibsen, whom Shaw admired and wrote about (see Shaw's The Quintessence of Ibsenism). "Exposition" means, basically, presenting those matters which inform the audience about the situation of the play and explain the main issues that are to become the central core of the drama. Thus, the play opens with a confrontation between a mother and her son, and through their conversation, we learn a great deal. For example, the entire conversation takes place because of the necessity of arranging financial support for Stephen's two sisters, and therefore the subject of Stephen's and his sisters' father must be brought up. This, in turn, allows the audience to know that the father's name has never been discussed by Lady Britomart and her children; thus, the topic is a highly embarrassing one for her son.
While Shaw is technically presenting his audience with the necessary background information for the drama which is to follow, he is also able, at the same time, to entertain his audience by playing up the conflict and the contrast between mother and son. Lady Britomart is a marvelous character; she is liberal enough to accept other peoples' opinions but only if they agree with her preconceived ideas. She adores advice from her son but only if it is the formulation of a course of action which she has already planned.
As her name implies, Lady Britomart is the epitome of everything that is British. In a classic work of early English literature, Spenser's Faerie Queene, one of the central characters is Britomart, a female knight, symbolizing militant chastity; thus, Lady Britomart becomes Shaw's symbol of militant upper-class English morality. She has been exasperated with her husband — not for anything immoral that he has done, but simply for the reason that he will not conform to what she considers to be the "proper" behavior for a person in his position. After all, he has proposed to disinherit his son in favor of a foundling, someone whom he has not even discovered yet — and all for the sake of a principle. Lady Britomart, in contrast, stands firmly within the philosophy of the English aristocracy, assured that no foundling can possess the qualities that a member of a noble family can have; her son is, after all, the grandson of a English earl, and yet while espousing these views, Lady Britomart is able to caustically castigate her future son-in-law, Charles Lomax, a member of the nobility, because of his basic incompetence. In fact, it is Charles Lomax's incompetence and his inability to earn money that makes it necessary to call upon Undershaft for future financial aid. Furthermore, Lady Britomart sees no discrepancy between disapproving of Undershaft and the manner in which he makes money and the fact that she has been completely dependent upon his money throughout all of these years. Even her son Stephen is shocked to realize that all of their present income comes from Andrew Undershaft. Consequently, this conflict between the family's reliance upon this money for their existence introduces one of the main themes of the drama — that is, the domestic dilemma will later be correlated with the dilemma of the Salvation Army when the Army will, finally, decide to gladly accept "tainted" money from "tainted" sources in order to insure its continued existence, and then it will pray for the "tainted" people who donated the money. Consequently, the domestic dilemma introduced in this first scene parallels one of the central themes of the drama.
This scene also prepares us for the appearance of other characters. Even though Lady Britomart is sharply opinionated, we are ready to accept her evaluations of some of the other characters. Later, we see that her future son-in-law, Charles Lomax, has been described by her in perfect terms; he is, indeed, something of a "noodle" — a rather fashionable but incompetent member of the aristocracy. Likewise, she snobbishly approves of having a scholar of Greek literature as a son-in-law, but she is also very practical and knows that one cannot live on prestige and snobbery. Consequently, she has undertaken the practical steps of calling her former husband to meet his family for the sole purpose of getting additional commitments for financial support for their children.