Humanity Wiped: A one-shot story

What if every time something bad happened, no one remembered it?
That is the world that Alice lives in. If something bad happens, murder, war, kidnapping, etc. The world is wiped of their memories of the last three days. Some people remember, but they are taken away and disposed of. But Alice remembers everything. Ever since she was little. She has learned that telling people won't end well, so she keeps to her self. Until her best friend, Andy disappears.

This was a 1000 words or less story for English class. Please ignore that