"The Flash" season 2 will see the return of Rick Cosnett in the upcoming flashback episode.
In season 1, Iris West's (Candice Patton) fiancé died after an encounter with Dr. Harrison Wells or Eobard Thawne.
As it turned out, Cosnett's Eddie Thawne had a direct connection or relationship with the doctor.
In order to ensure that he will no longer return to Earth-1, Eddie decided to sacrifice himself for the sake of his fiancée and friends.
Now, he will return in a series of flashbacks or in Earth-2, and will help Iris make peace with the past so she could move forward with the present and future.
Here's a look at the synopsis for the March 26 episode of "The Flash" season 2 as posted on TV Line.
"After the shocking revelation that Zoom is Jay Garrick, Barry is more determined than ever to get back to Earth-2 to stop Zoom forever. Desperate to find a way to increase his speed, Barry decides to travel back in time and masquerade as his earlier self in order to get his arch-nemesis, Dr. Harrison Wells/Eobard Thawne, to teach him how to run faster. However, things don't go as planned and Barry is stunned to face a familiar foe Hartley Rathaway, as well as an old friend Eddie Thawne, Iris makes peace with her past in order to embrace her future," the synopsis read.
Meanwhile, the upcoming episode of "The Flash" season 2 will also see guest star Andy Mientus giving life to the character of Hartley.
One photo from the The CW also showed Hartley pointing what looked like a gun at Dr. Wells.
Another photo showed the dad talking to his daughter Jesse Quick (Violet Beane).
One photo also showed Grant Gustin's Barry Allen/The Flash being trapped in the room where the other villainous characters are trapped after a major ruckus.
Another photo showed Hartley attacking and Jesse, in an attempt to get something out of Dr. Wells.
By the looks of it, Hartley could probably be asking the doctor for some information that he doesn't want to give away.
"The Flash" season 2 will return to The CW on March 26 at 8 p.m. ET.