Welcome back, Grimmsters! Season four picks up exactly where season three left off and it's not looking good for Captain Renard, who is taken into surgery after his shooting.
Nick, Hank, Trubel and Juliette, meanwhile, are in the Captain's SUV trying to figure out how Adalind took away Nick's Grimm powers and who the man that attacked Trubel and the Captain was. Juliette, having the answer to one of those questions, reveals Adalind got Nick to sleep with her after she transformed herself to look like Juliette. An awkward hush falls over the car, but not for long, as the four arrive at Nick and Juliette's house, which is swarming with cops. To get through this, they all agree each of them must be telling the same story.
In a different part of Portland, a man sorts through flashes of memories about the military, equations and a family in his mind. He knocks on the door of Henry Slocombe, who lets him in after the man - Lawrence Anderson - says they share a mutual friend. Once he's in the door, Anderson woges and attacks Slocombe with four tentacles he drills into the back of Slocombe's head.
Inside Nick's house, Sgt. Wu flips through the Grimm books, immersed in what he sees, until Nick and Hank arrive. When Wu recognizes Trubel, Nick admits it was she who killed the shooter. Wu gives Nick and Hank a tour of the crime scene and identifies the shooter as FBI agent Weston Steward. The detectives on the case, Pogue and Meachum, prepare to question Trubel but they are interrupted by the arrival of Special Agents Chavez and Reston.
At the same time, Anderson finishes stealing Slocombe's memories but Slocombe's girlfriend, Alexandra, unexpectedly enters and catches him in the act. Faced with no other option, Anderson kills her and flees in Slocombe's car.
Trubel's walk-through of what happened with Agents Chavez and Reston goes smoothly and the pair asks Trubel to come back to the precinct to make a statement. Miles away in Austria, Viktor receives word that Renard has been shot and Steward is dead. He instructs his henchman to make sure Steward is linked to Nick and not Viktor.
Back in Portland, Anderson phones his employer to tell him there's a problem. The mystery contact is not pleased but when he learns there's been collateral, he informs Anderson he's on his way. At Nick's house, Agent Chavez discovers the Grimm books - and woges! Looks like Trubel's true identity isn't a secret anymore.
After the police leave, Juliette is left alone in her mess of a home. But not for long - Monroe and Rosalee soon arrive, and despite Juliette's protests, insist on skipping their honeymoon to help their friends. Trubel is officially questioned at the precinct by Meachum and Pogue while Chavez and Reston watch through a two-way mirror. Her story remains the same so Trubel is released, but it doesn't seem like we've seen the last of Agent Chavez.
Using Slocombe's memories, Anderson logs in remotely to a corporate account and begins transferring files. Slocombe's colleagues are alerted to this activity but Anderson finishes before they can do anything about it. Meanwhile, Hank visits Capt. Renard at the hospital and chats with Wu, who says the images in Nick's books resemble the Aswang he thought he saw. When Wu admits he's still having nightmares, Hank is tempted to tell him the truth. But before he can, a doctor interrupts and breaks some bad news: The Captain isn't going to make it.
At Nick and Juliette's house, Rosalee says they must figure out what was in the bottle the Captain wanted Nick to drink. When Nick and Trubel enter, Juliette once again drops the bombshell that Nick lost his powers after sleeping with Adalind. But after Nick explains how Adalind transformed herself, Rosalee worries Adalind used a Zwillingsschwestern Verflucht, an entwining twin curse, and heads to the spice shop with Monroe to search for a remedy. Trubel wants to head to the trailer to do more research, but Juliette insists on everyone getting some rest. As Trubel heads to her room, Nick offers to sleep on the couch but Juliette says no.
Sleep doesn't come easily for Nick, however, as he keeps picturing his tryst with Adalind. He finally gets up and begins cleaning the blood stains on the floor. Juliette comes down sometime later and grabs a sponge to help. As they clean, Nick wonders if perhaps no longer being a Grimm is the best-case scenario for their relationship. That's probably true, but is that the best-case scenario for Nick?
The next morning, Wu greets Nick and Hank at Slocombe's home, where Alexandra's body has been found. Wu tells the pair that Slocombe couldn't remember anything when he was questioned and that a neighbor reported seeing his car drive off. At the hospital, a doctor shows Nick and Hank the grisly photos of Slocombe's wounds. With a Wesen attack being the most likely cause, Nick and Hank head to the trailer.
Now parked in a secluded section of the woods, the trailer is hard to find and not easy to get to, but Trubel manages just fine and even gives Nick and Hank a fright when she jumps out of the trailer wielding a sword. When Nick admits he needs her to crack the case, Trubel pitches in and identifies the Wesen responsible as a Gedachtnis Esser.
Nick and Hank catch a break when Anderson is brought in after being spotted driving Slocombe's car. Unable to tell if he's the Wesen they're looking for, Nick enlists Trubel's help. Sporting sunglasses to hide her Grimm eyes, Trubel attempts to mug Anderson in hopes of provoking him to woge. Ta-da! The plan works. After Trubel confirms Anderson is the Gedachtnis Esser to Nick and Hank, she sets out on his tail.At the hospital, Captain Renard's fate has taken a turn for the worse after a team of doctors and nurses is unable to resuscitate him. Eventually, they call his time of death, but the only person around to hear it is a mysterious blonde woman who's been keeping watch for some time.
Who is the mystery woman watching Renard? Is he really beyond saving? And can Trubel handle facing such a dangerous Wesen by herself? Tune in next week to find out.