The Swedish artist Anna Cassel (1860–1937) had left a relatively modest mark on art history until now. Her art is dominated by sweeping landscapes and cityscapes with motifs from the Swedish rural counties Jämtland and Västmanland, and from Stockholm. Cassel was also a close friend of Hilma af Klint’s. They collaborated both spiritually and artistically and were members of the Christian spiritualist group The Five, founded by Sigrid Hedman (1855–1922) and active from 1897 to 1907.
Almost a century after her death, we are now – for the first time – presented to many of the occult and spiritual paintings Anna Cassel also produced.

In two essays Cassel is introduced to a wider audience, and it is clear that the collaboration between her and Hilma af Klint was much deeper than previously known.