Inami waking up as a detective is crazy. She is alone in the well, yet there's a guy with her. That guy looks like Kazuta, the guy who got his head drilled and was also her accomplice. In her mind from the show, she had a child-like memory of him from the past. That childlike memory likely manifested as the guy with the snazzy cape. The only other person with Inami in a well right now is Hondomachi (aka best girl), but she's off having a wild adventure in the sky. The mystery guy's lifeless eyes mimic the lifelessness that Kazuta had in his eyes when he was helping commit the "Gravedigger" murders from the show.
Or I could be talking out of my ass. That's very likely too. Great chapter, and a nice new detective design to boot.