Karl Vollmõller was a German playwright and screenwriter (1875-1945). He is famous for two works:
-Der Blaue Engel (The Blue Angel), and
-Das Wunder (The Miracle).

The latter is the movie that made Marlene Dietrich famous. The film is a religious spectacular about a legend from the Middle Ages about a nun who runs away from the convent, meets a knight, has a series of mystical experiences, and is accused of witchcraft.

While she is gone, a statue of the Virgin Mary at the convent comes to life and takes her place.

This movie was so popular in Europe that it was filmed twice as a silent film and again as a 'talkie'. Later, it became a play in German (1911), then in London, and on Broadway (1924). An American film verson was made in 1959.