You are a detective and Xiao is your partner. You're both the best detectives around and you're currently investigating a recent case of serial murders. You've noticed the one thing they all have in common other than the murderers MO; is that they spoke to you a day or two before their deaths. You discuss with Xiao that you're worried for his safety and the things you've found in the investigation clueless to the fact he's the culprit, murdering them just because they talked to you.