In the aftermath of Kelly and Juliette's deaths, Nick's friends question whether he can handle the strain. Meanwhile, Trubel goes missing and Nick is blaming an FBI agent... and Adalind goes into labor.
With Nick on leave, Hank gets a new partner as he investigates the case of a seemingly mild-mannered accountant who is actually a vicious Wesen killer... with ties to the organization that killed Chavez. Meanwhile, Adalind moves in with Nick because she has nowhere else to go.
Four homeless Wesen children lose the "mother" that they kidnapped and decide to take Rosalee as their new mother. Meanwhile, Nick moves Adalind and Kelly to his new home, and Renard meets with Meisner for the first time since the King's death.
A man trying to kill a mobster is himself killed by a Wesen, and Nick and Hank determine that an old ritual is at the heart of the murder. Meanwhile, a mayoral candidate asks Renard for his support, Rosalee receives a letter from an old friend, and Nick and Adalind continue to adjust to living together.
While Nick and Hank investigate the deaths of two Wesen, Trubel recovers at the hospital. However, the Occultatum Libera have tracked her down and have their own plans. Meanwhile, Meisner contacts Adalind.
A local gang of Wesen attack Wesen shop owners, and Nick and Hank soon discover that the attacks are deliberate... and tied to the Uprising. Meanwhile, Trubel settles in at the fortress, and Renard films an ad for the mayoral candidate.
After the ambush by the group calling themselves Black Claw, Nick calls Meisner and demands to see the new Juliet. Meanwhile, a Black Claw attack wipes out the Council, and the team's prisoner is attacked while in custody.
While Meisner shows Nick the extent of the HW organization and reintroduces him to Eve, the detectives deal with a lakeshore killer who is mistaken for a legendary water monster and murders two people.
HW requests a meeting with Nick and his allies to determine if they are with the organization or against them. Meanwhile, two bodies turned up ritualistically murdered, and Nick discovers that they are connected to an ancient Wesen ritual ... that isn't complete.
Monroe's Uncle Felix comes into possession of a cache of Grimm journals, which could hold the key to Nick's and Trubel's pasts... and the location of the Templar cache. However, two Black Claw killers will stop at nothing to get the journals.
Nick and Monroe use the key map to find the location in Germany where the Seven Knights hid their treasure. In Portland, an assassination closes in on Renard and the mayoral candidate that he's supporting in the election.
While Nick and Monroe search the catacombs in Germany, Hank, Wu, and Renard try to bring Dixon's killer to justice. Meanwhile, Tony pays Rosalee a visit, and Adalind discovers that her Hexenbiest powers are returning.
A maskmaker for Luchadors kills a Wesen to obtain his face... and make a mask from it for a young Luchador client. Meanwhile, Adalind worries about what happens if she reverts to her Hexenbiest nature, and Eve looks into Andrew's assassination.
Nick and Hank investigate a pair of murders that lead them to a family inflicted with a Wesen genetic disorder. Meanwhile, Renard arranges a meeting with Adalind, and Eve continues her investigation into Andrew's assassination.
Nick and Hank investigate a young girl's murder... where she aged 70 years overnight. Meanwhile, Renard considers running for mayor, and Eve continues her investigation of Black Claw.
A preacher uses his Devil-like Ween form to convince his audience that he is possessed by Satan and then casts him out. While Nick and Hank investigate, Eve gets closer to Rachel than she expected when she disguises herself as Renard.
Nick and Hank investigate a decapitation murder and discover that it is tied to an ancient Wesen ritual. Meanwhile, Eve warns Adalind not to harm Nick, Monroe and Rosalee explore the tunnels, and Adalind applies for her old job at the law firm.
Two corpses turned up dead, their bones liquified and then extracted from their bodies. while Nick, Hank, and Monroe track down the killer, Wu deals with his ongoing transformation. Meanwhile, Renard arranged a secret meeting with Adalind.
While Wu deals with his nightmares, Renard and a Black Claw representative both give Adalind an ultimatum.
Nick realizes that Adalind is with Renard, and Renard arranges a meeting with the Grimm to explain his options. Meanwhile, Zuri lets a Black Claw agent into her house to clone Hank's phone, but he catches on and realizes that Zuri is connected to the enemy.
Black Claw closes in on Nick and his allies, framing Hank for murder and wiping out HW's compound. Meanwhile, Diana's attempts to force Renard and Adalind together threaten Black Claw's plans.
With Nick in custody, Black Claw makes its move and launches attacks on the entire team. Eve is mortally wounded and the cure may be worse than the injury. Meanwhile, Rosalee tries to find the right time to give Monroe some important news.