Marie Roux is one of the three protagonists in The Lost Girls of Paris. Marie was raised in England, but because she is half-French and spent her childhood summers in Brittany, a region in northwest France, she speaks fluent French without a noticeable British accent. This is one of the attributes that leads to her recruitment by SOE. The chapters narrating Marie’s experience all take place in 1944, although Marie appears again in 1946 when she meets Grace in New York City.

Marie is a single mother. For much of the novel, her young daughter, Tess, lives with Aunt Hazel during the war. Like many children, she was evacuated from London for safety before the bombing blitz. Marie’s love for her daughter fuels her resolve during her work for the SOE, for she wants to “create a fairer world for Tess to grow up in” and “create a new story for her daughter” (65). Upon realizing this, her hesitation transforms into determination, and she uses her personal connections to motivate her in near-impossible situations behind enemy lines.

Marie is characterized by her questioning mind. She always wants to know the reasons for people’s decisions. Marie’s curiosity made her childhood harder and threatens to make her a poor undercover agent because she must learn to follow orders without questioning them.