i dont know what to do after i get past the guard and talk to the ripper dude?
Spoiler
Not sure, but I think that at this point you more or less have to walk around and look at everything you can, and eventually head back inside the domed area.
If that's not the part you're at, then,
Spoiler
you should be looking to bring down the roof in the dome so you can shed some light on the situation...
Hope that helps.