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 and Hank are called to the gruesome murder of a veteran working in home security. During their investigation, they discover this might be one of several revenge killings regarding a horrifying cover-up involving members of the army and military contractors. On the domestic front, Monroe accompanies Rosalee during her long overdue reunion with her mother and sister. In Europe, Adalind sees hints of what she thinks might be her powers returning.

When a local Reverend reports that his church has been robbed, Nick quickly learns that it’s a Wesen church, and enlists Monroe to check for any suspicious activity regarding the shepherd’s flock. Meanwhile, Nick and Juliette continue to figure out the rules of their relationship as a dangerous opponent lurks in the shadows with his sites on Nick.

A series of disturbing crime scenes leads Nick and Hank to the resurrection of an old feud that's all too familiar for Nick and Monroe. With the news of a royal family member's demise, several key players start to make their move. Meanwhile despite his recent trauma, Nick finds himself healthier than normal and Monroe and Rosalee talk about moving their relationship forward.

As a deadly crime spree begins to surface, a century-old urban legend takes shape in Portland's sewers and becomes Nick's latest case. In Europe, Adalind meets Prince Viktor, who’s come to bring those responsible for his cousin Eric’s demise to justice. Meanwhile, Captain Renard responds to the recent attempt on his life.

While trying to work out the ramifications of his new alliance with Renard, Nick investigates a murder where the victim was blinded with parasites sprayed into her eyes. Meanwhile, Juliette's hallucinations become clearer, and Adalind asks for help with her pregnancy.

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.

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.

An investigation into a grisly murder leads Hank and Nick to a seemingly unstable man who is on the run with his daughter; Monroe realizes that filling in for Rosalee will be harder than he thought.

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 and Hank are on the case as repeat instances of apparent vigilantism have whispers of an old Spanish legend making their way through a working-class Portland neighborhood. Elsewhere, Juliette learns the truth about Nick’s mother. Meanwhile, Adalind has a brief scare during her ultrasound.

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 investigate a Wesen "healer" whose ability holds risks that far outweigh its rewards. Meanwhile, Juliette takes in a friend when domestic issues escalate and Hank makes a move on his physical therapist Zuri. Elsewhere, Captain Renard finally tracks down Adalind and has a stern warning for her.

Nick and Hank find themselves thrown into the middle of an ancient battle and things heat up when the Wesen Council decides to get involved. Monroe and Rosalee fill everyone in on early Wesen history. Meanwhile, Sgt. Wu is still reeling from the events he recently experienced. As things heat up in Europe, one of the Resistance’s most trusted allies gets compromised as he tries to protect Adalind.

Nick realizes a series of child abductions that he is investigating bear a striking resemblance to the Hispanic legend of ``La Llorona.''

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.

Nick and Hank discover a new kind of strange when they investigate suspects being found dead - for the second time. In Europe, Adalind finds herself in the middle of a feud between Frau Pech and Stefania while working over the details of her pending transaction. Meanwhile, determined to remember every last detail to get things started once more, Juliette insists Monroe share with her Nick’s darkest secret - the world of Grimms and Wesen.

A panicked Juliette, Monroe, and Rosalee enlist Hank's help in fending off a zombie hoard while trying to figure out what happened to Nick. Knowing the truth, Captain Renard takes measures to help rescue Nick from the clutches of his brother, Eric. Elsewhere, along with the help of the mysterious Stefania, Adalind finds herself facing her most gruesome task yet in her effort to regain her Hexenbiest abilities.

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."

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.

A local maskmaker is targeting Wesen to create Luchador masks that bestows great power to its wearer. As Nick, Hank, Monroe and Rosalee work to stop the killings, Capt. Renard considers an offer that will bring him closer to claiming his destiny. Meanwhile, Eve's further investigation of a recent incident raises new questions.

A barbaric family history is revealed when Nick and Hank investigate a case of breaking and entering. Meanwhile, Nick assigns Monroe to look after Aunt Marie.

The station is abuzz as Nick and Hank are called to a case where an innocent flash mob results in a gruesome homicide. As Nick delves further into the investigation, he learns more about his unique family history, and finds himself at odds when he and Hank are assigned to protect a dark character from his recent past.

Nick and Hank investigate a murder victim left in a dumpster, and soon discover that the trail leads to an abusive boyfriend, an arrogant lawyer, and a meek junk yard owner. Meanwhile, Juliette notices someone watching her and Nick, and Monroe gets a message from the creature community.

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