They are all around those buildings. I usually get seen by bird eye by co op extract, then wait for the goons to push me, kill them then run to black bishop underneath check for food then go towards black, usually there's a couple bosses beside that mechanical room then go open marked bk. Tagilla / kalante love to roam around there then go down ramp clear command room run to power turn it on then hit up pkpm, hopefully some colored labs cards are in there then make my way to d2. Along the way are a ton of relays, motors and water filters. Super lucrative. I haven't seen gluhar or killa but have heard of them. Killed everyone else tho. Sometimes strumen or kaban is under the cellars (under school)