David Giuntoli

Nick's about to get into big trouble — Bigfoot trouble, that is.

On Friday's Grimm (9/8c, NBC), Nick (David Giuntoli) begins to investigate a mysterious case in which the suspected Wesen (guest star Kenneth Mitchell) is suffering from a mysterious malady that prevents him from returning to his human form completely. A therapist (guest star Roger Bart) attempts to suppress the creature within. Unfortunately, science isn't quite up to the challenge, and the side effects are appalling.

From Castle to Grimm: A user's guide to TV procedurals

Nick isn't the only one caught up in the frightening circumstances. Check out this clip of a few amateurs who encounter more than they bargained for out in the field:

Echoes of The Blair Witch Project, right?

Grimm airs Fridays at 9/8c on NBC.