The Mathus Station was a space station attacked by a Chaos Cult, called the Hounds of the Ruined Sky. The Imperial Fists defending the station were hard pressed to combat the massive cultist horde as they sought to kill the Space Marines. The long siege lasted nearly two hundred years and the cultists even built a little civilisation there, breeding generations of themselves to fight with Space Marines. In the end, there were only four Imperial Fists left out of twenty two. It was only after the Blood Angels responded to the distress signal coming from the station that the cult was finally destroyed.