Nick and Hank search for a dangerous heartbreaker who leaves behind a gruesome corpse and apparently her finger. Nick and Juliette's safety is threatened when the creature world begins to discover his identity.

When a brutal vigilante homicide is made public, it sends Portland’s Wesen community into a frenzy. As Nick investigates further, he discovers a pattern similar to that of a particularly brutal line of past Grimms. Is there another Grimm in town, or is Nick dealing with a sadistic copycat? Meanwhile, Captain Renard takes it upon himself to offer Juliette comfort in handling her ongoing dilemma with Nick.

Nick and Hank are called to the scene of a gang-related homicide. The case escalates as Zuri, Hank’s physical therapist, and her brother get caught up in the investigation. Meanwhile, Juliette seeks advice from Rosalee in dealing with the news that her friend is Wesen.

After Monroe’s abduction by the Wesenrein, Nick gathers the whole team, including Wu, to track him down and return him to Rosalee. As the search intensifies, Juliette learns more about her new reality as a Hexenbiest.

When a man is found dead with all of the bones in his body seemingly liquefied and removed, Nick and Hank find themselves in the middle of a gruesome family arrangement. Meanwhile, Wu deals with a crisis of his own and Hank reunites with his old flame, Zuri (Sharon Leal).

Deadly attacks on a team of scientist lead Nick, Hank and Wu on a investigation unlike any they have had before. Meanwhile, as the research continues into the origins of the cloth, Monroe and Rosalee learn that Eve is still feeling the after effects of the death grip. Elsewhere, Capt. Renard reaches out to an old friend to get answers to the origins of the symbols drawn by Diana.