The second season of "The Flash" has seen a lot of speedsters come into the story. Of course there is Barry Allen aka the Flash (Grant Gustin) and the show later brought in Jay Garrick (Teddy Sears), Zoom (Tony Todd), Jesse Quick (Violett Beane) and Wally West (Keiynan Lonsdale). And now the show is adding Eliza Harmon aka the Trajectory.

According to a report from TVLine, Eliza Harmon is described as a brilliant scientist but suffers from a split personality complex akin to Dr. Jekyll and Mr. Hyde. However, it is hinted the character will only have a short appearance on the show, given that she will only be a guest character for episode 16, with no future episode currently lined up for her.

In the original DC comic books, Eliza Harmon is also known as a speedster known as the Trajectory. She idolized The Flash and wanted to be like him. When Lex Luthor initiated a program that could grant people superpowers, she took the chance to become a speedster and named herself Trajectory.

However, the procedure altered her state of mind and drove her to near insanity. She eventually had to take a drug called the Sharp to slow herself down. Eliza later died when retaliating against Luthor.

Given that Lex Luthor is not in "The Flash," it is likely Eliza's origins will be altered to better suit the story of the show. It is possible that she may be one of the metahumans from Earth-2 or may have used her intelligence to replicate the process that gave Barry and Jay their powers but in doing so also deranged her mind.

At the moment no actress has been cast for the role but it is likely an official announcement will be made soon, at least prior to the episode she is set to appear in.

"The Flash" season 2 will return from its midseason break this Jan. 19.