C855 clue convergence

I didn't expect that Old Tu would invite me out alone after work at night.

"Since you don't want to expose this matter, then I'll help you investigate this case thoroughly when I'm free." The Old Tu sat on a bench in the park. He was wearing sunglasses as he spoke to me while tilting his head.

"Can you not do it like a secret agent? If you want to help me, just say it on the phone