Grimm has been throwing us a bone or two here and there, hoping to keep us interested in that overarching plotline about Grimms vs. Reapers and what's really going on behind Nick's back. So far, the episodes have limited themselves to a couple of minor mentions about the idea, then backing off to continue the episode's main event about what bad animal Nick's chasing next.
Now, however, there's also another subplot developing about Nick's girlfriend Juliette slowly finding out about who Nick really is. There are people watching her home, there are kids egging their house, and it's frankly freaking Juliette out a little bit, especially with all of the weird cases that Nick's been getting lately.
"Of Mouse and Man" happens to give us a little more of the Reaper mystery, too, once Monroe gets pulled into the fray. He's called out to give a clock a little fine-tuning, but instead of doing any work, he's beaten to a bloody pulp by a group of bad dudes who want Monroe to stop meddling in the affairs of a Grimm. "Organ Grinder" finds Nick's police captain Renard receiving a threat for helping the Grimm as well, and if you thought that the writers had forgotten about the large plot arc that they created in the first two episodes, you're dreadfully wrong.
Again, these episodes of Grimm follow a distinct pattern, the same that they've been doing each episode. But I've got to hand it to the makers of the show - they really know how to capture my interest with each subsequent creature. "Of Mouse and Man" explores the relationship between the shy real life guy and the mouse Wesen that he is underneath his outer visage; there's also a snake man thrown in there to rile things up, and that makes it more interesting because Grimm is not just showing us creatures mixed into the human world, it's also assimilating them within our culture and attempting to show the defining characteristics of each of us within the Wesen world. Perhaps you'll find a Wesen that exemplifies your own traits while watching.
The next two episodes, "Organ Grinder" and "Tarantella," get really gruesome with some excellent baddies. "Organ Grinder" explores homeless life and the ease of exploiting them by using them for organ harvesting; "Tarantella" tells a particularly sad story about spider people, spinnetods, who must vomit their acid into an unsuspecting victim in order to maintain their youthful appearance. Grimm isn't just interested in letting the audience watch Nick fight baddies; it's also trying to tell a particularly good fairy tale with a moral, and that's one thing that doesn't get tiring, even if each episode follows a formula.
Characters are still working well together, and Monroe and Juliette become more involved in each episode. At this point, the shows overarching plot has kind of hit the backburner, but that's okay with me - I can never wait to see the next Wesen Grimm decides to show us.