A barbaric family history is revealed when Nick and Hank investigate a case of breaking and entering. Meanwhile, Nick assigns Monroe to look after Aunt Marie.

The station is abuzz as Nick and Hank are called to a case where an innocent flash mob results in a gruesome homicide. As Nick delves further into the investigation, he learns more about his unique family history, and finds himself at odds when he and Hank are assigned to protect a dark character from his recent past.

After investigating a strange cluster of female deaths and disappearances, Nick sends Monroe undercover to get a whiff of a hypnotic suspect. In the meantime, a stranger shows up looking to avenge the death of his friend at the hands of a Grimm, but he'll have to get past Captain Renard.

Nick and Hank's investigation of a dead high school teacher leads them to the school's outcast, Roddy. Nick realizes that there's more to Roddy than meets the eye, and enlists Monroe's help to get through to the troubled teenager before he exacts revenge on the students who wronged him. Meanwhile, Nick learns that his presence is beginning to affect the creature world.

Nick is called to a suspected arson case, which exposes a longstanding family feud that brings Monroe face-to-face with characters from his troubled past. While Monroe wrestles with restraining his wild side, it's up to Nick to keep everything from going up in flames.

A mysterious homicide deep in the woods leads to Nick and Hank reopening a long-cold missing persons case. When Nick suspects this abducted person might be a feral creature, he asks Monroe to help remind this wild child of her human nature.

A prison escapee returns to Portland and seeks revenge on everyone who got him arrested. Nick notices his unusual strength and high tolerance of pain and calls Monroe to help put his rampage to an end.

Nick and Hank investigate a murder victim left in a dumpster, and soon discover that the trail leads to an abusive boyfriend, an arrogant lawyer, and a meek junk yard owner. Meanwhile, Juliette notices someone watching her and Nick, and Monroe gets a message from the creature community.

After some of Portland's homeless youth go missing, Nick discovers a black market supplying the Grimm world with human organs. As the investigation continues, Nick and Juliette befriend a pair of homeless siblings, Hanson and Gracie, whose friends have gone missing.