Fans of NBC's "Grimm," a dramatic cop series with a dark and fantastical twist, will have to wait another week before a new episode airs. Instead, NBC will air its "JFK 50th Anniversary Special" this Friday, Nov. 22, but the series will be back on the 29th with its new episode, titled "El Cucuy," in which a vigilante stalks Portland.

The upcoming episode of "Grimm" promises to be intense when an ancient Latin legend named "El Cucuy" mercilessly kills people living in Portland. Nick and Hank will be on the case as repeat instances of apparent vigilantism indicate that El Cucuy has made its way through the working-class Portland neighborhood.

This occurs while Juliette is going to find out the truth about Nick's mother. In the meantime, Adalind will endure a brief scare during her ultrasound, according to Hollywood Hills.

TVLine has learned exclusive information regarding Monroe's parents, who will be introduced on the show later this season. Dee Wallace from "E.T. the Extraterrestrial" and Chris Mulkey of "Friday Night Lights" will play the Wesen's mom and dad, Alice and Bart.

Before the season began, series co-creator/executive producers David Greenwalt revealed to TVLine that the clock enthusiast's folks would make an appearance related to Monroe and Rosalee's wedding.

"They're a little old-fashioned," Greenwalt warned, implying that Monroe's purist folks may not approve of their son being romantically involved with a Fuchsbau, in addition to being friends with a Grimm. As a result, Monroe must convince his parents to open up to his way of life or risk destroying his relationship with them.

"Grimm" S3E5 is set to air on Friday night, Nov. 29 at 9 p.m. on NBC. Watch a clip from the episode below: