By Natalie Abrams
March 18, 2017 at 07:07 PM EDT
Bettina Strauss/The CW

Warning: This story contains minor spoilers from the Invasion crossover. Read at your own risk!

Though Sara seemed poised to give up her mission to prevent her sister’s death during the four-way crossover, the Legends of Tomorrow leader hasn’t lost hope just yet.

During the Arrow hour of the crossover, Sara (Caity Lotz) was given the chance to bid Laurel (Katie Cassidy) farewell in the Dominators’ Matrix-like construct, telling her sister, “Some things you just can’t fix.” By the end of the Legends of Tomorrow episode, Sara noted to Oliver (Stephen Amell) that getting to see a version of their life had they not landed on the island — which leads to them becoming heroes, but also to years of pain and loss — was a gift, rather than a curse.

While it sounds like Sara has a found new sense of acceptance, her mission is far from over. “This is, by no means, resolved in Sara’s mind,” executive producer Marc Guggenheim tells EW. “I don’t know if it ever can be. She’s not only lost her sister, but she knows that there’s circumstances or there’s realities out there that make the possibility of bringing her sister back a real thing for her. But those possibilities are blocked by other realities — the reality that you can’t change history without major repercussions.”

“She recognizes that right now there’s no way to save Laurel without doing damage to the timeline,” Guggenheim continues. “I wouldn’t even say she’s made peace with that, it’s just that she’s come to realize that much in the same way that Barry [Grant Gustin] has realized that he can’t save his mother without doing damage to the timeline.”

Much like Sara, viewers also got a sense of closure with Laurel’s return in Arrow‘s 100th episode. “Even though the show has evolved, Laurel is at the heart of it,” executive producer Andrew Kreisberg says. “She was Oliver’s great love, she’s Sara’s sister, she’s Lance’s daughter. Even if we do get to 200 episodes, Laurel will always be at the heart of the series and be such an important character, and, on top of that, Katie Cassidy will always be so important to us. We were so happy that she agreed to come back because she is part of the family, both behind the camera and in front of it.”

Read more:

Arrow boss on that Artemis betrayal

The best nods to the past in Arrow’s 100th episode

Supergirl boss on what’s next after those winter finale reveals

Arrow EP reflects on 100 episodes

EW’s cover story on the four-way crossover

What was cut from the Arrowverse crossover?

The Dominators will return on Supergirl — here’s why that’s scary

Invasion vs Arrowverse: Here’s what’s different from the comic

The Flash: More Flashpoint repercussions to come, but…

Why Lynda Carter wasn’t the Earth-1 POTUS of the Arrowverse

Supergirl will return in 2017, while the winter finales of The Flash, Arrow, and DC’s Legends of Tomorrow air Tuesday, Wednesday, and Thursday, respectively, at 8 p.m. ET on The CW.