"Grimm" season 4 is just a few episodes away from its finale and episode 20, "You Don't Know Jack," is going to kick things off with a bang as it involves a string of homicides. The homicides become too much of a problem that the press starts asking Captain Renard if there is a Jack the Ripper copycat roaming the streets. 

Nick, Hank, Monroe, and Wu set off to begin their own investigation, but according to the official synopsis, the team comes across something they never expected before. No hints have been given and even the promotional trailer doesn't reveal any clues regarding what they discover. 

The bigger twist involves Juliette. In the previous episode, she turned into a full Hexenbiest when she discovered Adalind is pregnant, bearing Nick's child. Adalind previously slept with Nick by disguising herself as Juliette. Now the real Juliette is embracing her Hexenbiest form to harm anyone that comes across her path. 

In this episode, she sides with an unexpected ally who may understand her actions and motivations. Last episode, Nick found hope for her in Adalind after seeing how someone like her could change for the better. Perhaps Juliette would find someone to help her turn back the way Adalind did. 

However, according to Cartermatt, she may have embraced it too far to the point where there is very little chance of her getting treated. The site asks if she even wants to be helped at this point because she may have already accepted being a true Hexenbiest. 

Both Adalind and Rosalee have to work together in a last-resort effort to treat Juliette. Whatever differences and issues they've had will be put aside in order to bring Juliette back and restore her humanity. 

"Grimm" season 4 episode 20, "You Don't Know Jack," is set to air on May 1 on NBC.