The Flash returns to The CW tonight (February 8) for its ninth and final season, and showrunner Eric Wallace has warned fans of an emotional conclusion for the Arrowverse.
"There's lots of tears amongst The Flash family these days," he told Entertainment Weekly. "It's the last season premiere. We all know Stephen Amell is coming back to the show, and it's the last time we get to work with Stephen as the Arrow."
He continued: "It's the last season finale – there's all these lasts happening and that's really bled into the season themes, which is how finding closure allows you to achieve a new beginning."
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Wallace also admitted that, while he didn't expect the series to end on his "watch" when he took over during season four, he knew exactly how the final episode should look.
"Quite frankly, once I took over, I knew what the final scene and final shot of the series finale should be," he explained.
"I've known exactly what even the final line of dialogue should be. Everybody's going to find out long before the ending because it plays into the title of the final episode."
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Giving fans a little more insight into what they can expect from the finale, he added: "There's some very special things, you're going to see a lot of familiar faces from the past popping up here and there, and it all ties into something that Barry's been struggling with ever since season one.
"I can't say more than that. Let's just say the events of season one are still unresolved and Barry doesn't realise it until this year.
"Resolving those issues provides the emotional climax for our series finale at the end of season nine."
The Flash airs on The CW in the US. Sky Showcase and NOW air the show in the UK.