
Marguerite sailed from New York on December 5, 1918, aboard the French ocean liner Espagne, but even before she arrived in France, she was reminded that this was no holiday excursion. The ship struck an underwater mine in the Gulf of Gascony, but managed to stay afloat as it slowly crept toward its port.
After docking in Bordeaux, Marguerite boarded a train that took her to Paris. Passing the Obelisk of Luxor where the guillotine once executed enemies of the French Revolution, Marguerite made her way to No. 4 Place de la Concorde and the office of Colonel Ralph Van Deman who now was in charge of counterintelligence for the Paris Peace Conference.
Marguerite and Van Deman later gave different accounts about her mission to Germany. She wrote that her orders were to show the Sun’s morale-boosting movie, Miles of Smiles, to Maryland troops in France, and then travel to Germany posing as a reporter to gather information on the economic and political conditions in Berlin and the attitudes of the people.

Van Deman recalled that Marguerite’s mission was to keep an eye on the approximately one hundred newspaper correspondents assigned to cover the peace conference. When Van Deman later learned that American Communist Robert Minor was distributing propaganda leaflets to U.S. troops, Marguerite volunteered to go to Germany to persuade Minor to come out to either British- or American-held territory, where he could be arrested.