system
Given the following post, respond as if you're commenting on Reddit:
human
[Warhammer 40k] You are a relatively high up person on X World and you encounter a Purii Genestealer (and get away unscathed). What do you do to alert The Imperium, and what happens as a result of that?

So you encounter a tyranid genestealer in its purii form. It doesn't spot you, but you see it and are able to capture irrefutable proof of a genestealer infesting the planet you inhabit, be it video footage or whatever.

For the sake of argument, you are high up enough in your respective planet's government so that somebody would at least look at your evidence and not just dismiss it out of hand.

How would you go about informing the right people about the infestation, and what would happen as a result of you informing them on the following world types?

1. A Hive World

2. A Forge World

3. An Armory World

4. A Shrine World


Extra Note: You only encountered one genestealer, but you don't know how many others are on the planet or whether they have infected anybody or begun a cult yet.
gpt
Citizen,

Your failure to notice a xenos infestation is a massive dereliction of duties and responsibilities as part of the ruling class. Purii Genestealers are only encountered in Space Hulks and last stages of a genestealer infestation. And genestealers are never, ***NEVER ALONE!!!***

The signs of genestealer infestations are appallingly apparent. The first outward signs would be cults growing disappropriately in size and strength, often as deviations of the Imperial Ecclesiarchy. Next would be massive riots across the planet. That your failure to report this in the annual reports reeks of heavy genestealer infiltration within the upper echelons of the planetary government. The final stage would be the sightings of purii genestealers and the jamming of all astropathic communication within the subsector. That signals the imminent arrival of a Tyranid Hive Fleet.

As of this time, an Imperial Exterminatus Fleet is prepped to purge your subsector of all biomass to deny the xenos. You will not survive to receive this message. Your heirs and descendants are stripped of all rights and property on the charges of dereliction of duty and heresy. May the Emperor have mercy on you.

The Emperor protects.

Inquisitor BuddhaFacepalmed, 

Ordo Chronos.