"The Flash" season 1 is nearing its finale and for those looking for "The Flash" episode 19 spoilers, Television Promos have the synopsis of the upcoming episode.

"Joe (Jesse L. Martin) and Cisco (Carlos Valdes) head to Starling City to continue their investigation of Dr. Wells (Tom Cavanagh)," the source wrote. "While in town, the duo enlists the help of Captain Lance (guest star Paul Blackthorne), and Cisco meets the Black Canary (guest star Katie Cassidy), who asks him for a favor."

The source continued, "meanwhile, back in Central City, Barry (Grant Gustin) races to catch a meta-human named Hannibal Bates (guest star Martin Novotny) who can transform himself into every person he touches - which includes Eddie (Rick Cosnett), Iris (Candice Patton), Caitlin (Danielle Panabaker) and even The Flash."

Here's a sneak peek of the upcoming episode to be released on April 21.

The episode director is Wendey Stanzler and the script was written by Ray Utarnachitt & Cortney Norris.

Meanwhile, we have previously reported that executive producer Greg Berlanti confirmed  Gorilla Grodd will be dealt with in season 1.

"I wouldn't say teased. I would say we're going to deal with it this year," he said. "The comparison I make is a little bit to Slade the first year on Arrow in the sense of we started with the mask in the pilot and then we saw which way we were going. He was, ultimately, in the back half of that first season even more than we would ever do with Grodd this first year because... We're going to have to get the technology right and all the stuff right to make it look and feel real."

He added, "but a lot of times, we do this stuff not as a tease as much as a challenge to ourselves of, 'Can we do it?' Grodd's definitely one of those, so we hope we pull it off."