
Portland detective Nick Burkhardt, descended from a long line of warriors known as Grimms, defends his city from magical creatures known as Wesen, which are part human and part animal. Fighting alongside his partner, Hank, colleague Sergeant Wu and friends Monroe and Rosalee, Nick faces off against internal and external forces, including his police captain, Sean Renard.

After Juliette stumbles upon a brutal murder, Nick learns the suspected creature and friend of Monroe is suffering from a mysterious condition, the inability to completely return to human form; this mysterious condition leads them to a therapist.

Nick tries to come to grips with the return of his mother; Monroe intends to awaken Juliette from her mysterious coma; Hank struggles with the shocking truths he has recently learned.

Nick and his mother continue to battle the Mauvais; Dentes, Monroe and Rosalee fight against the clock to save Juliette; details are revealed about the source of Juliette's illness, resulting in a showdown.

Nick lends his expertise when an old friend of Hank's asks for help finding his missing daughter.