The Flash: Eric Wallace Breaks Down Reverse Flash's Fate in "Negative Part Two"

The Season 8 finale of The Flash was as an action-packed episode that saw Barry (Grant Gustin) and Thawne (Tom Cavanagh) once again following the latter's stunning resurrection in last week's "Negative, Part One". But while that showdown was expected, the episode was also full of unexpected outcomes, including a death many fans may not have seen coming. Now, series showrunner Eric Wallace is breaking down that death and how planning for the episode to function as a series finale let the series pull it off.

Warning: spoilers for the Season 8 finale of The Flash, "Negative, Part Two", beyond this point.

In the episode, after Thawne's resurrection last week, he ended up being transformed by the Negative Forces into a super powered version of himself in order to take on and kill The Flash. When the pair fought, Barry was prepared to settle the score between the two foes once and for all, his rage and grief at Iris' death enough to push him to wanting to kill Thawne and, thanks to the return of the good Forces who in turn powered Barry, he had the ability to do so — or at least put up an incredible fight. But as the two speedsters fought, they began to put Armageddon into motion. Ultimately, thanks to the return of Iris, Barry came to understand that using that much power would not end well so he sat down and accepted the limits while Thawne made one last push only to be killed by his own power.

It's a death that Wallace said will stick, and as for why this episode was the right time? It turns out that the episode was written before The Flash had been renewed. The story was set to work as a series finale.

"Well, there's two things. One, this time Thawne did cross the line. He actually killed Iris in bringing about his resurrection," Wallace told ComicBook.com about what made this story the one for a final showdown. "When that happened, I knew story-wise that emotionally, it would push Barry Allen to a place where he'd never been before. A place where for the first time, he really is actually about to cross the line and consider killing someone. Because he's not reacting as our heroic Flash as we know him, he's reacting as a spouse and as a partner, he's reacting emotionally. I. knew this would be the one time where we could have a story… and how appropriate that it should be in a season finale, but one time we've got a story about a hero actually about to kill his arch nemesis. So, that was pretty terrific."

He continued, "Having said that, there's the other side which was, when we were writing this script and breaking the story, we thought this was the series finale, not the season finale. We thought this was the end. So, we're like, 'All right, well, we've got to have the final battle against the Reverse Flash, and he's got to die. We've got to push it as far as we can dramatically and tell the most epic story possible and present the most emotional battle that we can.' Then of course, right as we finish the script, we got the wonderful news that we would be getting a ninth season, which I'm very happy about."

With the show coming back for Season 9, it would be easy for the series to rely on the "comic book" nature of things and find a way to bring Thawne back yet again, but Wallace told us that, like the death of Frost, this will stick, though he doesn't rule out bringing Cavanagh back in some other capacity.

"We had to go, 'Oh, oops, oh. Hey, he's super dead. How do we come back from this?'" I have no idea, to be honest with you. I'm not going to worry about it, it made for a good ending," Wallace said. "We're going to take a break. We will have some new villains next year. The question is, will Tom ever be the Reverse Flash on our show again? I don't know, man, because just like Frost, the Reverse Flash of a negative Reverse Flash that he became, they are truly dead. But having said that, I can't imagine a season of The Flash without just a little bit of the awesomeness that Tom Cavanagh brings, in some capacity."

The Flash will return for Season 9 in 2023.