A knock at the door

Here, a knock at my door can mean many things.  Maybe someone has a question or wants to borrow something.  Often people just want to hang out and talk.  Sometimes people have adventures planned that you are to be part of.  Tonight a new reason cam into existence.  A knock at the door was to tell me that the police would be here soon about registration and I would need to talk to them.  It's China and things like this happen, so I just waited about 5 minutes for the next knock at my door.  Outside was Eric, one of our Chinese staff, along with about 8 Chinese police officers.  A few of them had their cameras and took pictures as I grabbed my passport to show them, they handed me a piece of pink paper reminding people about registering at the police station, and joked with me about wanting to teach me Chinese while I could teach them English.  5 minutes later they were gone, and I have another story to add to my What Happened in China list.