Now what do I do?

I have to finish a short story by next Wednesday. Until yesterday, this was fine. I had a beginning along with a sense of direction and developing characters. The problem began when my professor read the beginning to my story aloud in class and asked: "What do you think will happen next?" The class hypothesized while I stayed silent praying that no one had any guesses as to what could happen next. Unfortunately for me they guessed every direction I had planned on taking and then some. Should I write an ending they've already guessed or write a new story completely? Does it make me completely predictable that they've guessed my thoughts or was the beginning too foreshadowing? Does it even matter.

I've been muse hunting. There is someone I spotted for the first time today, actually. I tried to sneak a better peek but the only way I could casually approach him would be to use the restroom multiple times. This is really difficult.