The Flash's Barry Allen is about to learn that his timeline meddling will have consequences beyond his wildest imagination.

Three months after he saved his mother, the Scarlett Speedster's new reality is going well. The season 3 premiere will shatter that illusion, however, and the second episode will drive home the message - there are some things that can never be.

Titled "Paradox" (get it? "Flashpoint" and then "Paradox"), the hour will air on October 11. Check out the official summary below.

"Barry (Grant Gustin) realizes the effects from Flashpoint are much greater than he thought," The CW teased. "Meanwhile, Barry meets new co-worker Julian Albert (Tom Felton) and is surprised by Julian's immediate disdain for Barry."

We all know that Barry has a winning personality, but he's also steeped in secrets. If you thought he had a tough time keeping his alter ego on the down low, imagine how much harder it will be to keep his coworker from learning his origins.

To make matters worse, Julian (previously Julian Dorn) will transition to the original timeline once the Flash attempts to patch up his big mistake. There is no Julian Albert in DC, but his name is similar to that of Albert Julian Rothstein, a.k.a. Atom Smasher. As fans know, Atom Smasher came and went during season 2, but, considering season 3's "New Destinies" tag, there is always a chance the writers might take a second run at the character. 

"He's not familiar with me, but I'm familiar with him, so it's an odd dynamic. It seems like a love/hate thing at first," Felton told Sci-Fi Now. "He's a forensic expert so he treads on the toes of much of what Barry is good at. Hence they have a slightly abrasive relationship at first. I say abrasive, but I mean that - clearly because of the events of the season - none of the relationships that Barry has had with other cast members is the same."

In the meantime, the Flash will have to contend with the likes of The Rival (Todd Lasance), Doctor Alchemy, and Savitar. Life in the Flashpoint universe is certainly no picnic.

Catch season 3 premiere when The Flash returns to The CW on Oct. 4 at 8 p.m. ET. Click the video below to see a preview.