The 21^st episode of The CW's "The Flash" titled "Grodd Lives" is guaranteed to give fans of the show interesting and risky storylines.

Now that Harrison Wells/Eobard Thawne (Tom Cavanagh) is forced to regroup his plans after his identity as the Reverse Flash was revealed, Barry/The Flash (Grant Gustin) and his team have to deal with the circumstances of having a telepathic vicious gorilla living in the sewers from wreaking havoc in Central City.

This scheme was all a part of Wells' ruse to distract Barry and his friends, though, given that the doctor's main goal is to just get back at his own timeline. However, it looks like his personal vendetta against Barry is the effect of a significant event happening somewhere along the timeline, CarterMatt pointed out.

Hollywood Hills reported that the official synopsis for episode 21 reads: "Barry will have to deal with the Reverse Flash's latest threat to a member of the group. To make matters worse, Dr. Wells is going to unleash Grodd on the city in order to distract Barry and the team. Joe (Jesse L. Martin), Barry, and Cisco (Carlos Valdes) will head down into the sewers to catch Grodd but the gorilla will quickly get the upper hand after he kidnaps Joe. Iris and Barry are going to have a heart to heart talk."

Screen Rant noted that Grodd's existence has been teased ever since the show's pilot episode. It was revealed midway through the season that the huge ape was a test subject of Wells and General Eiling (Clancy Brown). Wells' control over the animal was due in part of Grodd's thinking that the doctor is its father.

Barry and Iris (Candice Patton) will have a turning point in their relationship now that she knows that Barry and The Flash is the same person. The previous episode "The Trap" also saw Barry now fully aware that he is destined to marry Iris in the future. He was, however, unable to share this knowledge with her and her current boyfriend Eddie (Rick Cosnett), Digital Spy wrote.

Conclusively, "The Trap" hints at romantic entanglements for Barry and Iris' future, particularly about the possibility of Iris professing her love for the superhero again.

CarterMatt also claimed that the Killer Frost storyline will not be abandoned this season, so fans should expect noteworthy changes for Danielle Panabaker's Caitlin Snow at some point in the upcoming episodes.

Den of Geek reported that the upcoming episode is directed by Dermott Down from a script written by Grainne Godfree and Kai Yu Wu.

Episode 21 of "The Flash" will air this coming Tuesday, May 5 at 8 PM on The CW. Check out the promos for the episode below.