During the investigation of an accident site, Nick discovers a disease that is quickly spreading; Monroe and Rosalee come across an infected creature; Captain Renard gets a tip about a dangerous fugitive.

Angelina comes to town with bad news; Nick asks Hank for help keeping Monroe safe; Captain Renard receives a visit from a past acquaintance.

Hank and Nick investigate when a high school competition turns deadly; Capt. Renard is faced with an unwanted infatuation.

When a brutal vigilante homicide is made public, it sends Portland’s Wesen community into a frenzy. As Nick investigates further, he discovers a pattern similar to that of a particularly brutal line of past Grimms. Is there another Grimm in town, or is Nick dealing with a sadistic copycat? Meanwhile, Captain Renard takes it upon himself to offer Juliette comfort in handling her ongoing dilemma with Nick.

Adalind returns to wreak havoc as she avenges her mother's death; Captain Renard's obsession escalates; Monroe receives a surprise visit.

Nick, Monroe and Hank discover that members of a Wesen community have been responsible for a series of bank robberies; Juliette questions her mental state.

When a gruesome homicide brings an office party to a screeching halt, Nick and Hank find themselves battling a Wesen on a completely new platform - online. Meanwhile, Juliette's mysterious hallucinations finally start to take shape, giving them a whole new meaning.

Nick 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 meets a powerful new ally in Europe. Meanwhile, Juliette seeks out help after becoming overwhelmed by the latest side effect of her recovery – multiple memories of Nick showing up everywhere.

Nick discovers a muse-like Wesen 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 arranges a dinner date with Nick in the hopes of clearing the air, but their plans go awry as the case intensifies. Meanwhile, Rosalee takes her first visit to Aunt Marie’s trailer.

Just when things look like they’re back to normal with Juliette, Nick is called to investigate a flurry of rage-fueled assaults happening all over Portland. He goes to Monroe and Rosalee for help battling Portland’s newest wave of "undead." As if that weren’t enough, Captain Renard informs Nick that his brother Eric is in town on family business. Meanwhile, Stefania and Frau Pech methodically use their alliances with Adalind to battle one another.

Monroe, Hank, Rosalee and Juliette track down a manic Nick and do all they can to find him and reverse what's been done to him before he causes any more damage. Meanwhile, Captain Renard does his best to clean up the zombie fallout on all fronts - domestic and international. Elsewhere, the more time Adalind spends with Stefania, the more disturbing things seem to get in her quest to regain her Hexenbiest abilities.

When Nick and Hank investigate a drowning death with mysterious marks on the victim’s ankles, they happen upon a group of water-bound Wesen with a deadly postcoital cuddle. Meanwhile, Rosalee starts unpacking her things at Monroe’s, and Captain Renard makes a startling realization about the possible identities of the Royal Baby’s parents.

Nick faces his toughest challenge yet when he and Hank investigate a case that combines religious phenomenon with the dark dealings of the Wesen Council. Meanwhile, Rosalee is torn when Nick's case challenges her Wesen loyalties. Elsewhere, Captain Renard leaves town to tend to some "family matters."

After a string of delinquent teens go missing, an old Wesen tale of an evil Santa who brings more than just a lump of coal may be the prime suspect. The investigation intensifies as Nick and Hank take things a little too far. Meanwhile, Monroe enlists Juliet to surprise Rosalee for their first Christmas together with unintended results. Elsewhere, Captain Renard’s tour of Europe brings him closer to tracking down Adalind.

Nick and Hank are called to the scene of a gang-related homicide. The case escalates as Zuri, Hank’s physical therapist, and her brother get caught up in the investigation. Meanwhile, Juliette seeks advice from Rosalee in dealing with the news that her friend is Wesen.

Nick and Hank investigate a cop killer who scalps his victims. Meanwhile, Juliette begins to communicate with Nick's mom via email and Adalind finds herself much closer to delivering her baby than she previously thought. Elsewhere, Monroe's parents decide to surprise him and Rosalee with an early arrival to Portland after learning some exciting news.

A horrible new predator creeps into Portland with its sight set on a young expectant couple who are close friends of Sgt. Wu. Nick and Hank must figure out how to deal with Wu as the investigation escalates. Meanwhile, Adalind prepares for a special delivery while her enemies are hot on her trail.

A double homicide leads Nick and Hank to a traveling carnival where the performers are not what they seem. To get a better understanding of what's going on behind the scenes Monroe and Rosalee go undercover. On the wedding front, Monroe has a really important question for Nick. In Austria, an invaluable member of the Resistance makes the ultimate sacrifice to help Adalind.

Nick and his mom, Kelly Burkhardt, join forces to protect Adalind's baby. Meanwhile, Prince Viktor activates a deadly stateside asset to find Adalind and her child.

When Nick brings Trubel on a ride along with Hank, they end up investigating the murder of a young woman; Adalind is hopeful after making a discovery.

Rosalee and Monroe's big day arrives; a realization shakes Juliette and Nick's relationship to its core; Adalind's plan leads to a catastrophic event.

The Gedächtnis Esser continues to steal memories and Captain Renard's mother visits him in the hospital to try to save his life. Meanwhile Wu confronts Nick about Trubel and Nick and Adalind share a psychic connection.

A rabbi raises a golem to protect his nephew, but he can't control it. Elizabeth successfully recreates Adalind's spell, but it still requires a key ingredient.

With Monroe and Rosalie are dealing with a growing problem from Wesen purists, Nick and Juliette must decide if a normal life is really what they want.

A traveler manages to bring a blood‑sucking legend with him as he shows up in Portland. Nick and Hank investigate the gruesome trail of “El Chupacabra.”

Nick and Hank investigate a series of murders that lead back to the Wesen Council and a mysterious bounty hunter. Elsewhere, Juliette’s meeting with Henrietta brings about more disturbing news than she was expecting. Meanwhile, Adalind and Viktor make their way back to Portland.

Nick and Hank investigate a murder victim with his foot cut off, and stumble onto a disturbing Wesen take on the "lucky rabbit’s foot." In an effort to help, Monroe and Rosalee go undercover. Meanwhile, the fallout from Adalind and Juliette’s showdown still has Nick reeling and sends him on a path that leads to Henrietta.

A cyclist's homicide introduces Nick and Hank to a Wesen with a tragic fatal touch. Captain Renard and Adalind learn the Royals have stepped up their efforts to find their child, and another member of the Royal family is introduced. Meanwhile, Juliette ponders the idea of embracing what she's become as opposed to fighting it.