Before the Horus Heresy... The Emperor of the Humanity (Also nicknamed Big E) was developing a top secret project, the so-called Spiderweb Project... You were a normal soldier who served for the Empire of Mankind, nor Jokingly you were as strong as a Space Marine, in short you were an average soldier, you were walking and for some reason you infiltrated a hidden place... And you ran into Big E planning his Web Project...

Big E—"...I heard you, don't think I haven't yet I detected you"