Although neither had any associations with the film industry, Janowitz and Mayer wrote a script over six weeks during the winter of 1918–19. In describing their roles, Janowitz called himself "the father who planted the seed, and Mayer the mother who conceived and ripened it". The Expressionist filmmaker Paul Wegener was among their influences. The story was partially inspired by a circus sideshow the two visited on Kantstrasse in Berlin, called "Man or Machine?", in which a man performed feats of great strength after becoming hypnotized. They first visualized the story of "Caligari" the night of that show. Several of Janowitz's past experiences influenced his writing, including memories of his hometown of Prague, and, as he put it, a mistrust of "the authoritative power of an inhuman state gone mad" due to his military service. Janowitz also believed he had witnessed a murder in 1913 near an amusement park on Hamburg's Reeperbahn, beside the Holstenwall, which served as another inspiration for the script. According to Janowitz, he observed a woman disappear into some bushes, from which a respectable-looking man emerged a few moments later, and the next day Janowitz learned the girl was murdered. Holstenwall later became the name of the town setting in "Caligari".