Smile

At a psychiatric ward, Dr. Rose Cotter meets patient Laura Weaver, a PhD student who witnessed her professor take his own life. She claims to be the only one who can see an entity that pretends to be other people smiling at her. Laura then has a sudden mental breakdown, and convulses on the floor. As Rose calls for help, Laura smiles at her before taking her own life, cutting her own throat with a shard from a broken vase.