In the early 20th century, during the years after World War I, the derogatory phrase “surplus women” denoted unmarried working women. Discussions using this phrase appear throughout the novel as a recurring motif related to the theme of Challenges Facing Women in 20th-Century Europe. The novel suggests that the debate over working women at this time was deeply entangled in the larger debate about women’s rights. During World War I, the absence of men in the workforce enabled women “to take on employment previously out of reach” (58). After the war, working women were expected to give up their jobs to returning soldiers. However, because nearly a million British men died during the war, many British women remained unmarried. Without husbands to support them, these “surplus women” were forced to “support themselves in perpetuity, almost always at low-paying jobs” (58). Although working gave women like May Daniels some measure of independence, it also exposed them to “scorn” from members of the public who believed that the “natural state” of women is marriage and motherhood.

French investigators attempt to paint May as a “surplus woman” to reduce public concern about her death. Although the Queens of Crime work hard to uncover May’s personal life, demonstrating her bravery and fortitude, the label sticks. In the novel’s final chapters, a secretary named Miss Bennett kills Sir Alfred Chapman on behalf of herself and May Daniels, considering it “vengeance for them both and for every ‘surplus’ woman” (294). The novel’s final description of May as a surplus woman suggests that the label was difficult to lose.