The Endymion Cluster, the stellar region given to the Mantis Warriors to guard as one of the Chapters of the Malestrom Warders, was a region of Imperial space composed of 20 settled planets (6 of which were of major importance) that lay to the direct galactic east of Terra in the dangerous but resource-rich Maelstrom Zone of the Ultima Segmentum. The Cluster was surrounded on all sides by unsettled wilderness space and had never proven to be politically or economically coherent enough to be accepted as a fully-organised Imperial Sector since almost all of the human-settled planets within the Cluster were pre-industrial Feral and Feudal Worlds. The Endymion Cluster was located at an impressively dangerous astrographical position, with the horrors of the Maelstrom Warp Rift behind it and the