Following yesterday's promo for The Flash that introduced us to Rick Cosnett's Eddie Thawne, The CW has released a new promo that showcases Danielle Panabaker's Caitlin Snow. She is a biogeneticist that is studying the effects a freak electrical storm has had on Barry Allen's body.

The character actually debuted in a Season 2 episode of Arrow, with the actress describing how Caitlin interacts with Barry Allen (Grant Gustin) on the show, although it still isn't known if her character will ever turn into the villain Killer Frost. Take a look at this brief video, then read on for details about how the show will eventually introduce Wally West.

In The Flash, two of the other main characters are Candice Patton and Jesse L. Martin as Iris West and her father Detective West. As fans of the comic book will know, Wally West was another version of The Flash, and in the original comics, Wally was an older, caucasian male. However, DC Comics' New 52 reboot turned Wally into a younger, African-American street kid.

Over the weekend, executive producers Greg Berlanti and Andrew Kreisberg revealed that they made the West's African-American so they can eventually introduce Wally West.

After a particle accelerator causes a freak storm, CSI Investigator Barry Allen is struck by lightning and falls into a coma. Months later he awakens with the power of super speed, granting him the ability to move through Central City like an unseen guardian angel. Though initially excited by his newfound powers, Barry is shocked to discover he is not the only "meta-human" who was created in the wake of the accelerator explosion - and not everyone is using their new powers for good. Barry partners with S.T.A.R. Labs and dedicates his life to protect the innocent. For now, only a few close friends and associates know that Barry is literally the fastest man alive, but it won't be long before the world learns what Barry Allen has become...The Flash.