Synopsis

A string of homicides have the press asking Captain Renard if a Jack the Ripper copycat has arrived in Portland. While dealing with the investigation, Nick, Hank, Monroe and Wu deal with a situation they never expected. Meanwhile, Adalind and Rosalee must work together on a last ditch attempt to fix Juliette's condition. Elsewhere, Juliette decides to help her new ally even if it means hurting those around her.

Grimm Season 4 Episode 20 (“You Don't Know Jack”) is episode 20 of 22 in Season 4 and first aired on May 1, 2015. It runs about 43 minutes. Directed by Terrence O'Hara. Written by Sean Calder and Michael Golamco. Guest stars include Danny Bruno, Rachael Perrell Fosket and Franchesca Agramonte. Grimm is a Drama, Mystery and Sci-Fi & Fantasy series from NBC.