The CW's hit series "The Flash" is slated to introduce a time travel element in the fifteenth episode of the season. Ahead of that, executive producer Andrew Kreisberg tells Entertainment Weekly that this new power will have consequences both good and bad for the characters:

"There's an episode coming up where there is inadvertent connection to the Speed Force that results in probably our funniest hour as well as our darkest hour as the dangers of time travel come to light. It's a mashup between Back to The Future and Terminator-the good version of time travel and the bad version of time travel."

The show's star Grant Gustin says the episode is also influenced by the 1993 comedy "Groundhog Day" which will see Barry accidentally traveling at first, and then coming to realise the power that comes with what he's doing:

"It's a complete accident the first time [he time travels]. It's really confusing because now we're playing with timelines and we're having to shoot things a couple different ways. It's like a Groundhog Day-type element. It's really funny and really exciting.

He's not handling it incredibly well. It's freaking him out a little bit. He realizes, 'Holy shit, this an opportunity to change things with my family's past.' He doesn't know yet to maybe not do that, but that's where Barry's at when he realizes what he's just learned that he can do, that he can maybe save his mom."

Kreisberg also adds that: "After that episode, things are never going to be the same on The Flash." No air date has been set for the time travel episode yet.