WARNING: The following article contains major spoilers for "Starling City," the Arrow Season 8 premiere.

The premiere of Arrow's eighth and final season was, in the words of showrunner Beth Schwartz, a bit like It's a Wonderful Life, with Stephen Amell's Oliver Queen traveling to Earth-2, and seeing what the lives of his friends and family would have been like without him.

Schwartz told a group of journalists, including CBR, that once the writing team came up with the concept, they were excited to see “who we could get back, what their Earth-2 persona was, and looking at the pilot and re-creating those moments that we all love.”

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She explained that the premiere was a deep dive into “just what the character Oliver Queen/Green Arrow has meant to all of the other characters in the show and how he has affected everyone’s life. And so we went back through all the seasons to make sure he had that impact.”

That’s the reason, Tommy Merlyn, Oliver’s best friend, was the Dark Archer in this version of the story. “It was the most natural [thing], if Oliver wasn’t there, that Tommy would’ve gone bad," Schwartz said. "And it was just fun to see [actor Colin Donnell] in the Dark Archer suit.”

Another character with a very different fate in the Earth-2 timeline was Thea Queen, who overdosed on her 18th birthday. According to Schwartz, this had everything to do with where the character was heading in the show’s pilot.

“We talked about the pilot and when Oliver came back and [Thea] was a totally different sister than he remembered leaving," she said. "She was really heavily into drugs, and he saved her on her birthday in Season 1, so in talking about that, we’re like realistically if he wasn’t there she probably would have died, so that was the decision for this episode.” Of course Willa Holland will return this season as Earth-1 Thea, so we haven’t seen the last of the character.

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In the Season 8 premiere, Josh Segarra, who previously played Adrian Chase, aka the villain Prometheus, instead become Earth-2's Green Arrow -- and a funny one at that. Schwartz said Segarra "really brought more the comedic side, sort of making fun of himself a little bit. And… him not knowing who he was on Earth-1 just made it that much more fun for Stephen [Amell] to play off of." She added, "The two of them obviously have amazing chemistry. That’s why we all love Season 5. ... It felt like it just always made sense [to have Segarra play the Green Arrow.]”

Of the shocking ending that saw the destruction of Earth-2, Schwartz said the writing team knew they wanted to wrap up the premiere that way “pretty early” in the process. “We knew pretty fast that… when we started breaking the season as a whole – you know we don’t have that many episodes – so we wanted to start big and we wanted to introduce the upcoming 'Crisis' immediately," she said, "because that is what this season’s about, and what Oliver’s struggling with the entire time.”

Arrow Season 8 Batman cowl

She also clarified that what happens on Earth-2 “does indicate the Crisis in starting earlier than we thought.” The Arrow team had to get approval from the team at The Flash to destroy Earth-2. “They were very gracious,” Schwartz acknowledged.

Schwartz also mentioned that the look of that destruction was a big point of concern for everyone involved. In fact, the production team met about it many times. "It's such an important moment," Schwartz said. "It sets up the crossover… and we just wanted to make sure we got it right, so it was a lot of meetings, a lot of conversations.”

Of course, fans also took notice of the Batman mask at the beginning of the episode. On whether there will be more Batman Easter eggs in Arrow this season, Schwartz joked, “We’re just happy we can say Bruce Wayne now.” Then she said when it comes to Batman in the Arrowverse, that it’s more “Batwoman’s thing.”However," she did add, “now that [Batwoman is] in our universe, we’re able to get away with a lot more things Batman-related.”

Airing Tuesdays at 9 p.m. ET/PT on The CW, Arrow stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Rick Gonzalez as Wild Dog, Juliana Harkavy as Black Canary, Katie Cassidy as Black Siren, Katherine McNamara as Mia Smoak, Joseph David-Jones as Connor Hawke and Ben Lewis as William Clayton-Queen.

NEXT: Arrow Showrunner Talks Season 8, Guest Stars, and That Backdoor Pilot