In the next episode of "Grimm" season 5 titled "Skin Deep," Nick and Hank will be dealing with another Wesen who will use the fountain of youth to his advantage and to the doom of many.

The Wesen in question masquerades as a dermatologist and tricks young women into using a beauty regimen that he claims will prevent years from showing on their faces.

This doctor advises the use of an anti-aging cream that not only works backwards but also brings about killer consequences, as shown in one of the victims glimpsed in the "Grimm" season 5 promo.

This Wesen's victims are always found as if they aged a lifetime overnight. This is evident in the dead young woman Nick's party discovered, the same woman who will make them familiar with the age-manipulating Wesen.

In order to stop any more killings, Nick and Hank seek the help of Rosalee to see this doctor and make sure that he is the perpetrator of the crime.

Just as the doctor is about to make her his latest victim, Monroe charges into the room, wolfs up and tackles the killer doctor, whose face turns into a cluster of tentacles as seen in the "Grimm" season 5 promo.

Meanwhile, Adalind's problem with the re-emergence of her hexenbiest powers continues. She is still wrestling to tell Nick about it as well as her secret meetings with Renard about Diana.

In this "Grimm" season 5 episode, Adalind will find that she may have to team up with him so as to finally get Diana back, but this idea has 50 percent chance of going awry.

"What she has to do in order to get Diana back is the most difficult decision that she could possibly be forced to make," Claire Coffee, who plays Adalind's role, told TV Line. 

Meanwhile, Nick has its own secrets from Adalind of course. The biggest of which is the treasure chest sitting in a place accessible to Adalind – a spot that is not entirely secure and is vulnerable to exposure.

"Grimm" season 5 episode 15 "Skin Deep" airs April 1 at 9 p.m. ET on NBC.