| "You Don't Know Jack" | |
|---|---|
| Grimm episode | |
| Episode no. | Season 4 Episode 20 |
| Directed by | Terrence O'Hara |
| Written by | Sean Calder Michael Golamco |
| Produced by |
|
| Featured music | Richard Marvin |
| Editing by | Scott Boyd |
| Production code | 420 |
| Original air date | May 1, 2015 |
| Running time | 42 minutes |
| Guest appearance(s) | |
|
|
"You Don't Know Jack" is the 20th episode of season 4 of the supernatural drama television series Grimm and the 86th episode overall, which premiered on May 1, 2015, on the cable network NBC. The episode was written by Sean Calder and Michael Golamco and was directed by Terrence O'Hara.
Opening quote: "Catch me when you can..."
A string of homicides have the press asking Captain Renard (Sasha Roiz) if a Jack the Ripper copycat has arrived in Portland. Monroe (Silas Weir Mitchell) traces the mode of operation of the homicides to the Luxembourg Peasants' Revolt. While dealing with the investigation, Nick (David Giuntoli), Hank (Russell Hornsby), Monroe and Wu (Reggie Lee) deal with a situation they never expected. Meanwhile, Adalind (Claire Coffee) and Rosalee (Bree Turner) must work together on a last ditch attempt to fix Juliette's (Bitsie Tulloch) condition. Elsewhere, Juliette decides to help her new ally even if it means hurting those around her.
The episode was viewed by 4.22 million people, earning a 0.9/4 in the 18-49 rating demographics on the Nielson ratings scale, ranking third on its timeslot and eight for the night in the 18-49 demographics, behind 20/20, Dateline NBC, The Amazing Race, Hawaii Five-0, Blue Bloods, Beyond the Tank, and Shark Tank. This was a 10% decrease in viewership from the previous episode, which was watched by 4.66 million viewers with a 1.0/4. This means that 0.9 percent of all households with televisions watched the episode, while 4 percent of all households watching television at that time watched it.