Grimm: “The Hour of Death” (Episode 2.10)

Two Grimms aren’t better than one, especially if one of them is a genocidal psychopath out to destroy the Wesen population. Nick meets his match this episode in the form of a mysterious Grimm, whose mantra “all Wesen have to be killed” motivates the vigilante to terrorize Portland.
A girl is missing, and Nick believes he’s found the kidnapper, only to lose his suspect when there isn’t enough evidence for an arrest. So Nick plans to inject the suspect with truth serum to get a confession, but the psycho Grimm beats him to it. The result? The suspect is tortured into confessing on video and the girl is saved. But Nick and his cop buddies are left with the suspect’s mangled corpse and questions as to whether the end justified the means.
A twisted game of cat and mouse between Psycho Grimm and Nick ensues, with Psycho Grimm insisting that Nick is “a traitor to his kind.” Nick’s compassion toward friendly Wesen has become commonplace, and we’ve been lulled into believing Nick’s actions are the norm. But Psycho Grimm’s adherence to tradition (that is, kill anything inhuman) has jolted us out of our reverie. Nick is an anomaly, and he’ll always be at odds with “his kind.”