Was this a test?

 

I was the first one in the lab this morning and it was already here, just floating above the table.  There was no sound or odor that I noticed, but as I moved slightly left, it moved.  If I eased over to my right, it moved as well.  It’s like it could see me.  It knew I was here.

What was this thing?  Did it just manifest itself from the chemical residue left behind from yesterday’s class?  Is it dangerous?  Suddenly I was sorry I arrived so early.  Where the heck is the instructor?  What am I supposed to do now?