The House of Zarn was a settlement on the "vampire planet" in E-Space. It was one of the few settlements on the planet that were a considerable distance from the Hydrax. The only contact its inhabitants had with the outside world were Zarn's visits to the castle to meet with the Three Who Rule. During one such meeting, Zarn was infected by them and became a vampire. Upon returning to the settlement, he spread the infection to the entire population.