The second season of "The Flash" will feature a variety of new characters, all of whom will play crucial roles in the story when it resumes later this year.

Series star Grant Gustin told TV Line that the show would be expanding its cast significantly this season.

"There are a lot of new characters coming in, not just the ones that have been leaked online. And they all will challenge relationships, in good and bad ways," the 25-year-old actor said.

The death of Eddie Thawne in the first season's finale meant that actor Rick Cosnett will not be returning to the main cast, but most major characters will, according to Gustin. Even Tom Cavanagh, who plays the role of fake Harrison Wells/Eobard Thawne, is slated to come back.

In the show's sophomore year, Barry Allen will be getting a new love interest named Wendy, a "spunky, fun, and funny" science whiz. According to Cinema Blend, Wendy could actually be Patty Pivot, one of the protagonist's most recent romantic partners in the comics.

A new mystery hero called "John Clark" will also surface in the show. Described as "slightly cynical with an edge," he is being portrayed as someone whose unusual power will be difficult to control.

Fans can also expect a new villain who is expected to succeed Eobard Thawne as the show's "big bad." Gustin said in an interview with Latin Post that the villain would debut early in the season and described him as "a really cool 'big bad' one that's going to be revealed kind of immediately."

Season One ended with a cliffhanger, as viewers saw Barry speeding up to a black hole that was threatening to gobble up Central City. But according to Screen Crush, "The Flash" may not actually be the one who will be saving the world.

"The Flash" Season Two will premiere October 6 in its normal timeslot on The CW.