Nick and Hank search for a vigilante Wesen who is cleaning up the mean streets of Portland by brutally murdering evildoers.
A watery revenge killing leads Nick to discover a new Wesen species.
A centuries-long feud brings an unpleasant pop of crime to Portland.
While the gang tries to stop Zombie Nick's ruthless rampage and Renard exacts his revenge on Eric, Adalind works to restore her Hexenbiest powers.
A panicked Juliette (Bitsie Tulloch), Monroe (Silas Weir Mitchell), and Rosalee (Bree Turner) enlist Hank's (Russell Hornsby) help in fending off a zombie hoard while trying to figure out what happened to Nick (David Giuntoli). Knowing the truth, Captain Renard (Sasha Roiz) takes measures to help rescue Nick from the clutches of his brother, Eric (guest star James Frain). Elsewhere, along with the help of the mysterious Stefania (guest star Shohreh Aghdashloo), Adalind (Claire Coffee) finds herself facing her most gruesome task yet in her effort to regain her Hexenbiest abilities.
Monroe-mance is in the air, with this romantic mash-up of "Monrosalee" moments.
Just when things look like they're back to normal with Juliette (Bitsie Tulloch), Nick (David Giuntoli) is called to investigate a flurry of rage-fueled assaults happening all over Portland. He goes to Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner) for help battling Portland's newest wave of "undead." As if that weren't enough, Captain Renard (Sasha Roiz) informs Nick that his brother Eric (guest star James Frain) is in town on family business. Meanwhile, Stefania (guest star Shohreh Aghdashloo) and Frau Pech methodically use their alliances with Adalind (Claire Coffee) to battle one another.
Nick (David Giuntoli) and Hank (Russell Hornsby) discover a new kind of strange when they investigate suspects being found dead - for the second time. In Europe, Adalind (Claire Coffee) finds herself in the middle of a feud between Frau Pech and Stefania (guest star Shohreh Aghdashloo ) while working over the details of her pending transaction. Meanwhile, determined to remember every last detail to get things started once more, Juliette (Bitsie Tulloch) insists Monroe (Silas Weir Mitchell) share with her Nick's darkest secret - the world of Grimms and Wesen.
Nick (David Giuntoli) discovers a muse-like Wesen (guest star Nora Zehetner, "Heroes") with the ability to influence those she gets close to - some with positive results, others with terrifying ones. Nick must find a way to get close without losing himself in the process. Juliette (Bitsie Tulloch) arranges a dinner date with Nick in the hopes of clearing the air, but their plans go awry as the case intensifies. Meanwhile, Rosalee (Bree Turner) takes her first visit to Aunt Marie's trailer.
Mysterious cow mutilations and reports of glowing creatures put Nick (David Giuntoli) on a case that forces him to question the existence of aliens within the Wesen world. He also meets a strange UFO expert who seems to know more than he's letting on. Meanwhile, Nick digs further into the key, and Juliette's (Bitsie Tulloch) romantic memories of Nick start coming back in a big way.
Nick (David Giuntoli) finds himself fighting a wildly different sort of nature freak in a desperate attempt to keep a volcano from burying Portland in lava. Meanwhile a pregnant Adalind (Claire Coffee) meets a powerful new ally (guest star Shohreh Aghdashloo) in Europe. Meanwhile, Juliette (Bitsie Tulloch) seeks out help after becoming overwhelmed by the latest side effect of her recovery - multiple memories of Nick showing up everywhere.
While on jury duty, Rosalee (Bree Turner) tasks Nick (David Giuntoli), Hank (Russell Hornsby) and Monroe (Silas Weir Mitchell) to help stop a defense attorney from using his particular "Wesen wiles" to overturn what should be an open-and-shut murder case. Back at the precinct, Captain Renard (Sasha Roiz) brings Nick and Hank in on his own recent dealings with the Verrat, to keep them on their toes. Meanwhile, a return to the trailer brings a flurry of memories of Nick rushing back to Juliette (Bitsie Tulloch).
When a gruesome homicide brings an office party to a screeching halt, Nick (David Giuntoli) and Hank (Russell Hornsby) find themselves battling a Wesen on a completely new platform - online. Meanwhile, Juliette's (Bitsie Tulloch) mysterious hallucinations finally start to take shape, giving them a whole new meaning.
When a mysterious case of sudden blindness causes a woma's death, Nick (David Giuntoli) and Hank (Russell Hornsby) come across a disturbing Wesen that feeds off its victim's tears. Meanwhile, Adalind (Claire Coffee) contemplates the significance of her new situation, while Juliette (Bitsie Tulloch) continues to work with Rosalee (Bree Turner) in an effort to fix her memory.
The Wesen code of honor comes into question when Nick (David Giuntoli), Hank (Russell Hornsby) and Monroe (Silas Weir Mitchell) discover a series of bank robberies with Wesen using true natures as their disguises. Meanwhile, Juliette (Bitsie Tulloch) finds herself tormented by faint, slowly returning memories that cause her to question her mental state.
After Nick (David Giuntoli) learns about Juliette (Bitsie Tulloch) and Captain Renard (Sasha Roiz), he must deal with the consequences. Things get even more complicated when Nick is called to investigate his own crime. Meanwhile, the search for the key intensifies as Captain Renard finds Nick's trailer and makes a surprising alliance. With Rosalee's (Bree Turner) help, Monroe (Silas Weir Mitchell) informs Nick that they might be able to stop what's going on with Renard and Juliette before it goes too far. Elsewhere, Wu (Reggie Lee) responds to a bizarre shooting at Nick and Juliette's house.
In a double dose of Grimm, Nick and Hank hunt a vicious alligator Wesen in the sewers of Portland, then do battle with the legendary holiday villain, Krampus.
An incredibly rare creature that may or may not be Wesen. Traditionally, the Wesen council actively works to eradicate Grausen, as Wesen are often blamed for their evil deeds.
Juliette takes a risk to kill off Daniel's parasite.
Learn more about The Royals, the mysterious cabal of the Grimm world.
Nick digs for the truth behind a child who is believed to be possessed by a demon.
Nick and Hank solicit help from Monroe and Rosalee to deal with a possessed child.
Nick suspects a Wesen link when a priest is brutally murdered during an exorcism.
While Nick's attention is focused on a likely suspect at the station, the real El Cucuy strikes again.
El Cucuy is a mythical vigilante beast who preys on those who inflict harm upon others.
Nick investigates a vigilante murderer who is trying to clean up the streets in a rough neighborhood.
Monroe feels like something needs to be said.