Between December 1912 and April 1914, Franz Marc sent Else Lasker-Schüler 28 postcards, all of which depicted the wildest imaginations the two artists share. One of those postcards was a prototype of Marc’s most renowned (and mysteriously missing) work, The Tower of Blue Horses. In Blue is inspired by Marc’s paintings, Lasker- Schüler’s writings, and the fascination relationship between them.