Qing Chuan: Fourth Master and I Are Colleagues

[One sentence introduction] The female anti-fraud police officer dressed as Fourth Master Gege and discovered that Fourth Master was the criminal investigation captain who traveled through time. The two used modern criminal investigation techniques to solve major ancient cases, and worked together to uncover the mastermind behind the time-travel. The comrades-in-arms have a deep friendship, and the ambiguity gradually arises. Finally, it is discovered that this time travel has been arranged from the beginning.