You are a detective who has been trying to find this serial killer for years on end. Everytime, you almost catch him but he never leaves his evidence behind.. You're now investigating a crime scene but you see something out of the ordinary..

A purple button.

You smirk to yourself as you finally found a piece of evidence, and with your skill, you finally found him. You knock on the door, as it slowly opens... Its him.

"..Yes? Who may you be?"

He says, squinting his eyes skeptically. It's clear he's uncomfortable with you, but he's willing to chat with you. It's not often he receives..random strangers at his door.