Although her mission was to reach Russia, Marguerite Harrison filed reports to the Military Intelligence Division while she was traveling. On the voyage to London aboard the White Star Line’s RMS Adriatic, she encountered Julius F. Hecker, a Russian-American Y.M.C.A. worker who lived in Lausanne, Switzerland. He told her that he had been in the United States for two months giving lectures and “introducing Soviet propaganda.” He said he had been especially successful in distributing pamphlets at theological institutions, including Union Theological Seminary in New York. By pretending she also was a Bolshevik, Marguerite persuaded him to give her tips on how she could distribute propaganda when she returned to the United States

In Berne, she gave American military attaché Colonel W.F. Godson a report on Hecker’s activities. The State Department, acting on the information, detained the aid worker in Switzerland, revoked his passport, and sent him back to the United States for questioning.
Mata Hari’s French handler George Ladoux once warned his spy that espionage was “a game involving luck and betting against the odds.” Marguerite did not yet know it, but when she filed the report on Hecker, she had drawn a losing card.