Sto Lat Assassins Guild

[Hash moker]

How do I get into the guild...I can get to the room where Rosa stands (Contract room) but as to entering and advancing skills I have no idea. Looked at everything and there's a big closed and locked door......so am guessing I need a key. Been through the entire mansion and cannot find a key. Does anyone have any ideas / clues / help

Thanks loads

[riannon]

It uses a CS dorm key