You are an ever evolving hive mind in the world of the system. You will be invading a newly integrated world to eat and evolve.
Their tyranids!
Use plans!
Luck is a strange thing. Sometimes it keeps you out of the hands of the Black Ships as a young psyker. Sometimes it lands a Tyranid splinter-fleet on your doorstep. Maybe the Emperor has a plan for you; one that doesn't involve ending up in some monster's gullet. The galaxy is rarely a kind place - but perhaps your luck will hold.