Cult of the four wheeled emperor named

In late 11.019M42 the emergence of the genestealer cult on Mordecai Secundus began to have a significant impact on both sides involved in the ground campaign. The genestealer cults were up until this point believed to be a minor annoyance, poked out of hiding by the arrival of the Imperium, but on 1911.019M42 an organised band appeared out of the wastelands and attack the Death Guard near to the front lines on the western slopes of the Mekken plateau. The fighting was intense, and before the highly mobile xenos forces withdrew, they had badly mauled the Death Guard defenders.

Although this latest action resulted in a victory over chaos forces, Kutuzov spent no time rejoicing. These were not new allies, but a second force he now had to contend with, as well as evidence of an existential threat to the Imperium in the sector. Information was now badly needed. How prevalent was this "cult of the four wheeled emperor", and how long had it lain dormant in the squalid settlements and dilapidated factories of the Death Guard dominated planet? Was this a sign of a new rising tyranid threat in the region?