Silas Weir Mitchell Silas Weir Mitchell

A reformed Blutbad, Monroe (Silas Weir Mitchell) has cleaned up his act. So why is he still feeling the hate?

On Friday's Grimm (9/8c, NBC), titled "Of Mouse and Man," the seemingly mild-mannered Marty (guest star Fred Koehler) could be taking matters into his own hands after a history of abuse.

But what does this have to do with Monroe? Perhaps nothing specifically, but it looks like his decision to help Nick (David Giuntoli) with homicide investigations is costing him.

Check out this exclusive sneak peek of "Of Mice and Man":

That's not cool. Monroe just wants to live a normal life, fix watches, play the cello. We hope whoever did this to him gets some payback.

Grimm airs Fridays at 9/8c on NBC.

How can Nick keep his friends and family safe? Who's your favorite character on Grimm?