What Happened to the Lady on the First Floor? — Nicola Vallera

The old lady from the first floor is far too kind with everybody. She has an incredible collection of plants on her bow-window, and she has become famous among botanists. Although many people love her, someone hates her because of something happened ten years before. This person is planning to murder her and spies on her from his window. He has been waiting for ten years his chance to kill the old woman.