Now that you mention it, I kind of smell a distubring possibility of a Kyokou Suiri S1 happening to this show's pacing as well. To those unaware, the show is a very similar supernatural detective show, one which started strong with two episodic plots and then squandered ten whole episodes on one mystery at an absolutely glacial pace. S2 was paced massively better with the longest mysteries being at most 4 episodes (and this time having an amount of twists actually justifying the length), feeling a lot better.
I really really hope this show wraps up the case quickly in the next episode and then throws in something new, but I have a fear it may also be heading towards a "season finale" case taking up half the season (perhaps with one shorter case in between for padding), and if that's going to happen with the pacing we're currently seeing, that is going to be a painful watch. I hate to be pessimistic about the show because I had such a good first impression of it and am really liking the concept and characters so far.
Funny enough, this is the first thing to come to my mind too. It's a nice little song for an otherwise quite unremarkable show.