Don’t tell dad Barry messed up the timeline. John Wesley Shipp, who plays Barry’s father Henry Allen on the CW’s The Flash, recently brought up a scene from the Season 1 episode “Fast Enough” where Henry says he’d be disappointed if Barry rewrote history.

“Henry would be very, very concerned,” Shipp told ComicBook, citing a scene where Henry was in prison and Barry came to visit. “When Barry said ‘I could undo all of this, I could go back and save mom,’ Henry told him, ‘No. You can’t.’ There are unintended consequences to things. Things happen … the way they do and when you go back and you fool with something, you may be thinking you’re creating an idyllic present and future that you want, but it’s like a Pandora’s box: You have no idea what you’re opening.”

Dad’s right: Barry did just that at the end of Season 2, stopping the Reverse-Flash from killing his mother Nora. And the result? No relationship with Iris, no paternal father figure in Joe West, no friends at S.T.A.R. Labs, Wally West is also the Flash for some reason, and even Diggle will be changed. All of this will be played out in the Season 3 arc “Flashpoint,” loosely based on the 2011 universe-altering comic series from Geoff Johns.

The moment Shipp talks about comes from the Season 1 episode, “Fast Enough.”

Shipp — who also played Barry Allen in the 1990 series The Flashwill also return as Jay Garrick, the Flash from Earth-3, although Jay won’t be very friendly with Barry. Because Barry used the Speed Force to selfishly change his life, Jay will be less trusting of Barry and will be “emotionally cooler” towards him.

The Flash returns for its third season on the CW October 4.

Photos via The CW