Shadow -
spoiler:If anyone is curious - inside of the "staff only" room (the room where the thieves go when you finish the third test), there is a note and a key. The room itself is a simple cube with metal wall textures. The note basically tells you to forget about this room and get out. The key is for the door, in case it closed behind you. Nothing too exciting - just a barely accessable blueroom. I wouldn't suggest you try to get into it, unless you enjoy dying, but it isn't impossible. Just FYI
Next time I have a few spare minutes, I'll have to open this mission up again and see if I can beat Preno's time - can't have anyone stealing my title now can I?