In 1924, she began working as a freelance theatre critic until in 1927, Hans Feld, a friend of her brother, suggested she worked for him at
Film Kurier, one of many film trade papers in Berlin. She joined the
Film Kurier as a staff journalist, writing a mixture of articles and interviews and the occasional film review including the premiere of
Mädchen in Uniform. Most of the premieres and major commercial feature films were reviewed by the men on the staff but occasionally she was allowed to assess them. In 1932, with the rise of
National Socialism she became proof editor and reviewer-in-chief as members of staff began to leave Germany. In March 1933, just three months after
Adolf Hitler became Chancellor, Eisner fled Berlin to Paris where a sister lived. Here she lived precariously taking any job she could find (such as translating or babysitting) and working whenever possible as a freelance film critic for international journals and newspapers. In 1940, she was rounded up in the first
Rafle du billet vert and taken to the
Vel d'Hiv with hundreds of other single Jewish women. From there, they were transported to
Gurs internment camp in the Pyrenees, a concentration camp run by the French for the Germans. After a few months, she managed to escape and travelled to
Montpellier, where she enrolled briefly as a student before finding her way to Rodez and to Pastor Exbrayat, who helped her to obtain false papers; she consequently became Louise Escoffier from the Alsace region. She remained in touch with
Henri Langlois, who was in Paris, and was placing cans of film in secret locations around the country to prevent them from falling into the hands of the Nazis. One of those places was near
Figeac in central France, in the cellars of
Château de Béduer. Langlois instructed Eisner to go there to preserve the films (including
The Great Dictator). Eisner accomplished this in freezing cold conditions for a month before running out of money. In need of help, she managed to gain a job in a girls school in Figeac. Badly treated, she began to teach German to some Spanish girls living with the local school teacher Madame Guitard, who took her in; she stayed there until the
liberation of Paris in late August 1944. After the liberation of Paris, Eisner rejoined Langlois and became Chief Curator at the Cinémathèque Française, where over a period of forty years she was responsible for collecting, saving and curating films, costumes, set designs, art work, cameras and scripts for the Cinémathèque. At the same time, Eisner began to work in private on her book ''L'Écran démoniaque
later translated as The Haunted Screen
which she described in a letter to Fritz Lang as "a book on German silent film". She also published essays, articles and film reviews in journals including Revue du cinéma
, which later became Cahiers du cinéma. In 1952, Eisner published her most highly acclaimed book, L'Écran démoniaque
, her study of the influence of the spirit of German Expressionism on cinema, translated into English as The Haunted Screen'' in 1969. Eisner subsequently published studies of
F.W. Murnau (1964) and of
Fritz Lang (1976), with Lang's collaboration.
Murnau was awarded the Prix Armand Tallier in 1965 In the late 1950s, she became a friend of and mentor of
Werner Herzog and other leading young German film makers, including
Wim Wenders,
Volker Schlöndorff and
Herbert Achternbusch. When Eisner fell gravely ill in 1974, Herzog walked from
Munich to Paris in winter. Herzog commented: "It was clear to me that if I did it, Eisner wouldn't die."{{cite web ==Death and legacy==