Caity Lotz as Sara Lance
“Legends of Tomorrow” star Caity Lotz said that Sara Lance’s (Lotz) reunion with her late sister Laurel Lance (Katie Cassidy) in Season 2 finale of the CW series was “very emotional” and “nostalgic.” The CW

Sara Lance (Caity Lotz) will be reunited with her sister, Laurel Lance (Katie Cassidy), in Season 2 finale of “Legends of Tomorrow.” And although the siblings’ reunion takes place in just one scene, Lotz said that having the opportunity to work with Cassidy once again was “wonderful.”

“Katie and I hadn’t been able to do a scene together in years,” Lotz told TV Insider before the “Arrow,” “The Flash,” “Supergirl” and “Legends of Tomorrow” panel at PaleyFest on Saturday. “She feels like my sister now, so it was very emotional, nostalgic, and I think people will really like it.”

Executive producer Marc Guggenheim commended Cassidy’s performance in the finale. “I have to give a shout-out to Katie Cassidy,” Guggenheim said. “It’s only one scene, but man, she’s spectacular in it. It’s a scene we’ve wanted to do since the beginning of the season. We really wanted to get Sara and Laurel back together.”

READ: “Legends of Tomorrow” EP teases a surprise cameo in Season 2, episode 16

In addition to Sara and Laurel’s reunion, fans will also see the Legends break a key rule of time travel in the finale. Since the start of the series, the team has visited different time periods, with the exception that they couldn’t travel back to moments they had already been. But in the final hour of the season, “what we’re leading up to is breaking a rule,” Guggenheim teased. “That's what the Legends are going to do. It’s a little bit of our homage to ‘Back to the Future 2,’ with a Legends-esque spin. It has major consequences.”

Lotz added that “things are going to get really bad” for the Legends towards the end of the season.”They are going to have to do some things they shouldn’t be doing,” the actress said. “They’re going to have to break some rules and go against their own codes. The finale is the biggest episode we’ve ever done.”

Besides Cassidy, Guggenheim revealed on Twitter that Jack Turner — who is set to make his debut appearance as J.R.R. Tolkien in Season 2, episode 15 — will be back in the finale.

The finale (Season 2, episode 17) titled “Aruba,” airs on Tuesday, April 4 at 8 p.m. EST on The CW, while episode 15, “Fellowship of the Spear” airs on March 21 in the same time slot.