Die Schwarze Schwesternschaft. Ein Darkover-Roman

Blurb

City of Sorcery is a fantasy science fiction novel novel by Marion Zimmer Bradley in her Darkover series and is a sequel to Thendara House. It was originally published by DAW Books in October 1984.
In terms of the Darkover timeline, City of Sorcery falls in the era identified by the author as Recontact.