Once Monroe shows him that Renard is Juliette's lover, Nick can barely control the urge for illegal revenge. Assisted by just returned Rosalee, Monroe works out how the passion spell can be broken, and ultimately Renard convinces Nick they must work together. Meanwhile Adalind is released for lack of evidence and returns to Renard's traitor brother in Vienna, without the key, not knowing Renard found and stole it from Nick's desk.
Monroe's potion finally relieves Renard and Juliette's passionate obsession, so he and Nick can collaborate again, even closer then ever, with Monroe and Hank aboard, against the royal conspirators. Three youngster Wesen, Cole Pritchard, his girl Krystal Fletcher and his former cell-mate Gus, repeatedly commit robberies using their Wesen appearances as if masks. Monroe witnessed a bank robbery and alerts Nick's police team as well as the 'Wesen Council', as this is a blatant violation of the centuries old Schwaben code, which Amsterdam HQ chief De Groot orders ...
In Dominick Spinner's successful Portland games design company, several employees engaged in developing and testing a single video-game are, one by one, killed i the game and hours later for real, by similar gruesome devices. At each corpse a literary clue is found, an anonymous caller dares the police to identify him. Nick handles the case, using Wu's bachelor hobbies experience. Monroe helps work out what rare Wesen could be behind it. Renard is preoccupied with royalty parties rivalry.
After sleeping on it Nick decides it would be best for Monroe to take Juliette to the trailer. However, the trailer triggers more memories of Nick than Juliette may be able to handle leading her to seek the help of Pilar for insights into her current condition. Meanwhile Monroe fears Rosalee, who is serving jury duty, maybe under the influence of a toad dropping Ziegevolk who is jury tampering to win his case. Nick, Hank, Bud, Monroe and Rosalee hatch a plan to stop this Ziefevolk once and for all.
Ranchhand John is killed while accidentally bumping at night into Vincent, a blue-fluorescent feral performing one of the 27 raids on cows that went from Nebraska to Portland, actually harvesting bovine ovaries for his pregnant mate Jocelyn, with whom he keeps moving and hiding. Besides Nick, the case seems to be followed only by an 'ufologist' or alien-hunter, who in fact chases the very feral species. Monroe recognizes the print Nick made from his key as part of a medieval map as Swabia, Renard explains the keys combine into a map to a terrible treasure hidden by ...
Nick is back on lovers' terms with Juliette, who remains eager to learn about ferals. Nick must however give priority to the violent crime wave caused by zombies. As he feared, they are created by the voodoo 'baron', who sets a trap as instructed. Captain Sean Renard informs Nick about his mistrusting meeting with visiting European royal half-brother Eric and the counterfeit documents Eric had prepared at the castle. Still in Vienna, Adalind, poisoned by Pech to switch appearances, is seen roughly overtaken by the gypsy witch's family Popescu. Rosalee prepares a ...
Monroe (Silas Weir Mitchell), Hank (Russell Hornsby), Rosalee (Bree Turner) and Juliette (Bitsie Tulloch) track down a manic Nick (David Giuntoli) 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 (Sasha Roiz) does his best to clean up the zombie fallout on all fronts - domestic and international. Elsewhere, the more time Adalind (Claire Coffee) spends with Stefania (guest star Shohreh Aghdashloo), the more disturbing things seem to get in her quest to regain her Hexenbiest abilities.
A series of disturbing crime scenes leads Nick (David Giuntoli) and Hank (Russell Hornsby) to the resurrection of an old feud that's all too familiar for Nick and Monroe (Silas Weir Mitchell). 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 (Bree Turner) talk about moving their relationship forward.
When Nick (David Giuntoli) and Hank (Russell Hornsby) investigate a drowning death with mysterious marks on the victim's ankles, they happen upon a group of water-bound Wesen. Meanwhile, Rosalee (Bree Turner) starts unpacking her things at Monroe's (Silas Weir Mitchell), and Captain Renard (Sasha Roiz) makes a startling realization about the possible identities of the Royal Baby's parents.
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 Juliette to surprise Rosalee for their first Christmas together with unintended results. Elsewhere, Captain Renards tour of Europe brings him closer to tracking down Adalind.