In a nutshell this is what happened in last season’s finale; Monroe and Rosa Lee are preparing to get married. Adalind makes a deal with Prince Viktor to permanently get rid of the Grimm, Nick, for her child who she thinks Viktor has taken, but in reality Nick’s mom took her child away for safety from the Royals. FBI agent Weston Steward gets closer to finding Captain Renard to kill him on Prince Viktor’s orders. Captain Renard finds out that Adalind is planning to poison Nick and tries to warn him. He didn’t know that Adelind already gave him the poison and sealed his fate by posing as Juliette and having sex with him. Renard goes to Nick’s house only to find Trubel there. 
He tells her to give Nick this antidote to counteract the poison Adalind gave him. When he is about to leave Steward arrives at the house and shoots him. He then comes after Trubel. A fight breaks out and Trubel is finally able to behead him. She rushes to Monroe and Rosa Lee’s wedding, only to be ambushed by the wedding guests who are all Wesen creatures. She drops the antidote and it breaks. Nick, Juliette, Monroe, RosaLee, and Hank regroup back in the chapel dressing room where Trubel is there with them. She tells them about Renard, his suspicion about Adalind and her intentions, and the antidote he gave her. Monroe realizes that Nick is not a Grimm anymore, and that shocks everybody. They head back to Portland to get more answers.
In the season opener, the group finally arrives at Nick’s house which is now a crime scene. Nick and Hank are approached by Officer Wu and tells Nick that the captain is in critical condition and rushed to the hospital. He then notices Trubel and recognizes her as the college student shadowing Nick at a previous crime scene. Nick then announces that she is the one who killed the suspect by beheading him. Wu tells Truble to stay around so she can answer some questions. Just then two FBI agents appear at the crime scene. Agent Chavez introduces herself and her partner Agent Rostin to Nick and Hank. She tells them she is here to investigate the death of FBI Agent Weston Steward, and wants to question Trubel in the house of the crime scene. Freaking out, Trubel quietly follows them in the house. She carefully recreates her accounts of what happened. Even though her statement rules her out as a suspect, and killed the agent in self defense, Chavez still has reservation about her.
It seems like the investigation is a shut and close case, Juliette waits for the crime scene unit to leave before she enters her house. Nick and Juliette finally gets some alone time to discuss the Adalind situation. 
He swears that he did not know that it was her in the bedroom. He thought he was having sex with Juliette. She wants to believe him but it is not going to be that easy. Just then Monroe and Rosa Lee come to the house. They miss their honeymoon in order to help their friends. They are surprised to find out that Adelind pulled a powerful cloaking spell to eliminate his Grimm powers, and they are determined to find the cure for this. Nick can’t sleep and decides to clean up the blood in the living room, Juliette helps him. He tells her that this might be a blessing in disguise, now he can just be a regular guy and not the Grimm. Juliette doesn’t say anything, but in silence she agrees.
The next day, Nick and Hank is called in to a murder case of a woman and a delirious boyfriend claiming he does not know what happened. But his head shows four large holes where memory is stored. Nick and Hank later find out that they are dealing with a very dangerous Wesen creature, called a Gedachtnis Esser, which has a head like a octopus that uses its tentacles to extract memories and information from their victims leaving them delirious and demented. They later find the Wesen is hired to steal top secret information for a client. To fight this Wesen, they ask the only Grimm they know, Trubel, to help them stop this creature.
Captain Renard is struggling to stay alive, but is failing. The last scene his life sign goes flat, while a mysterious woman watches him in the distance.
This season is going rough for Nick, who lost his powers. His mojo is gone, how can he be useful if he doesn’t see the danger in front of him. Who is this mystery woman by Renard’s side? Is Renard dead? Will Wu be able to get some answers that he desperately needs? Next week is the conclusion to this week’s episode. We’ll dig more into why this new Wesen is in Portland. Will Trubel step up and stop this Wesen, now that she is new Grimm?
