Can I have a glass of water?

Mei-Lin, a young university student is having boyfriend troubles. One night while talking on the phone with him; she hears a knock on the door. Mei-Lin opens the door to find herself face to face to a 10 year old girl. Without saying much, the girl asks her for a glass of water. Mei-Lin goes to get the glass of water, comes to the door but finds that the girl is gone. The following night, the girl returns to her door, and asks for a glass of water. Mei-Lin decides to speak with the owner of the building and discovers a shocking truth.