(((((((IZ))))))) ask the landlord to check the apartment, and if he's not there, contact the police. The not knowing and hands being tied is going to drive you nuts, dont wait for tonight tomorrow,or whenever, some kind of action on your part, will help calm you a bit, even just a subconscious calming is beneficial. I know there's nothing I can say to fix this, or make you feel better, but please know that I'm listening and I care, keep me updated...