Write a scene (approx. 600 words) from the first-person perspective of a character who believes they are a heroic detective in a noir setting. However, use subtle environmental details, dialogue, and the reactions of other characters to hint strongly to the reader that the narrator is actually mentally unstable and potentially the antagonist. Do not explicitly state the truth. Focus on 'showing, not telling' through discrepancies between what the narrator describes and how the world responds. Use sensory details related to rain and neon lights to set the mood.