Even Biff Doesn't Know Her

She turned back towards her friends, but they were already down the hall. They must have walked away from her when she was trying to figure out what was happening. Sarah turned and looked towards the other end of the hall. Her boyfriend Biff was walking in her direction. She let out a sigh of relief, then approached him. "Biff, there you are. Why didn't you pick me up this morning? I was waiting outside my house for, like, forever." "Who are you?" he asked.