On the next episode of Grimm, Nick (David Giuntoli) and Hank (Russell Hornsby) will be facing one of their greatest challenges to date.

The next episode of Grimm, titled Stories We Tell Our Young, features a complicated case that involves a young boy whose ailments combine the spiritual as well as the darkness of the Wesen Council. The case also manages to challenge Rosalee's (Bree Turner) loyalties to the Wesen.

NBC released a promo for the upcoming episode of Grimm, in which the team completely divides on whether or not the boy is Wesen or possessed. The promo teases that the team has to decide whether to save the boy or save themselves.

Meanwhile, Captain Renard (Sasha Roiz) decides to leave town to deal with matters involving family, according to NBC's official synopsis for the episode.

The storyline involving Captain Renard taking care of family matters may have to do with upcoming guest star Alexis Denisof, who is playing Viktor Albert Wilhelm George Beckendorf, the first cousin of Eric Renard (James Frain). Viktor and the royals may understand Captain Renard's wanting to belong.

The royals "definitely understand that that's very alluring to him," Roiz told TVLine recently. "It's one thing that's missing from his life . . . that idea of belonging and having that sense of family, which was stripped away from him. They know how to play that and manipulate that."

Grimm season 3 airs Fridays at 9 p.m. on NBC.

Watch a trailer for the next episode of Grimm here:

Tags: Grimm NBC Grimm Spoilers