The sorority house

You wake up on the floor naked with nothing but a collar on your neck. You see that it looks like a living room in a house but the collar has a thick chain connected to a bolt in the middle of the room. You examine the bolt and find a keyhole there, presumably to release and move you around. Looking around you see that it's clearly intended to be a group of girls here. You test out the length of your chains but it's only about ten feet that you can walk.

Confused, you hear a noise coming from an upstairs area.