The Flash Season 5 Finale Ending Explained

The Flash season 5 finale helps set up Crisis on Infinite Earths.

This article contains major The Flash spoilers.

“Legacy” spent its entire final act neatly tying up all of its narrative loose ends. A little too neatly. In fact, those last 10 minutes or so of The Flash season 5 finale were so tidy that you were probably right if you started to get a little suspicious. After all, isn’t there a Crisis coming? But if you stuck around to the very end, the episode used the very first surprise the show ever dropped on us to tease the upcoming Crisis on Infinite Earths.

But a couple of things to note before we get to that…

Ralph Dibny, Detective

It does really appear that we’ve seen the last of Sherloque Wells. He’s back on his own Earth, enjoying time with the love of his life, who used her meta powers to open the door of Jitters there. But Sherloque was the last piece needed in Ralph Dibny’s evolution into the more detective focused character he’s known as in the comics. That was driven home by Ralph returning to his old office (with a stuffed baby giraffe and a bottle of booze…or was it Gingold?) to peruse some casefiles. The one he lingers on is marked “Dearbon.” Comics fans may note that Dearbon was Sue Dibny’s maiden name, so it looks like we’ll have a new Flash supporting character next year, and a proper love interest (and mystery solving partner) for Ralph.

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Cisco Takes the Cure

This is pretty self-explanatory. Cisco takes the metahuman cure (one of this season’s least appealing concepts), sacrificing his Vibe powers once and for all. You might question the logic of a character whose powerset includes dimensional travel when we know that Crisis on Infinite Earths, which has the entire concept of interdimensional travel pretty much baked right into its name, giving up said powers at this time. You would be right. But hey, poor Cisco doesn’t know what’s coming. Let’s see if the writers can write themselves out of this corner by November.

So why did he do it? After all, earlier in the episode his new girlfriend was more than understanding of his double life and the “realities” of dating a superhero. Well, it was a line that Thawne dropped on him about how it was Thawne’s attempt to murder Cisco (in one of the show’s all time greatest episodes) that made him “extraordinary.” We all know that isn’t true, but Cisco took it to heart, and it was the last thing he needed to hear to convince himself that his Vibe powers are a burden. 

Killer Frost Gets a New Costume

Cisco’s parting gift to Caitlin Snow for helping him with the cure and for “being a great friend” appears to be a new Killer Frost costume. We don’t see it in full, but expect Ms. Snow to have some properly stylin’ superheroic threads next season. Of course, they sure make this feel like it has an air of finality to it, which…isn’t great. Cisco is still a genius, and he was an essential member of Team Flash long before he got his powers, let alone learned how to control them. Hopefully this doesn’t mean he’s leaving STAR Labs behind for good, but the rumor mill has been working overtime about Carlos Valdes’ plans for leaving since 2018, so…we’ll have to see how this all plays out.

Nora is Dead

Well, at least Nora as we know her is dead. Or never existed in this timeline. As Thawne pointed out, the changes to the timeline that were made by changing Cicada’s destiny as well as the destruction of the dagger took a little while to cement themselves. Once they did, Nora dissolved into sparkly timestream mcnuggets. Her journal remained, apparently because of the time language writing within it, which I guess makes it a permanent relic of other potential timelines. But as Joe said, “we have to believe we’ll see her again,” and he’s probably right. Barry and Iris will still probably end up conceiving Nora, the question is whether that “new” Nora ends up taking on a heroic destiny. Then again, given Thawne’s remark to Iris, maybe they won’t have the chance…

Thawne Threatens Iris, Hints at Crisis

Whenever we’re dealing with, essentially, the season one version of Thawne (who remains the best villain in Arrowverse history), there’s an extra air of menace about him. But Thawne makes a point of acknowledging Iris with, “Iris, always a pleasure.” This is more than mere familiarity from season one. In the comics, Thawne murders Iris West via a vibrating hand strike to the brain, and TV Thawne has hinted at his ill-intentions towards her more than once. Since this Thawne is potentially 15 years more experienced than the last time we saw him, it’s possible that he already has future knowledge of a murder he has already committed. 

Then again, the Arrowverse is quite good at sticking to the spirit, rather than the letter, of its comic book source material. We may never see Thawne murder Iris West in this manner, but there does seem to be an undercurrent to his tone there.

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But Thawne makes an even more pointed remark, this time to Barry: “See you in the next Crisis.”

The Newspaper Date Changes, Crisis on Infinite Earths is Now

The infamous Central City Citizen headline first glimpsed in the very first episode of The Flash, dated April 25, 2024, has always had an air of finality about it. After all, it was the Arrowverse’s first hint that Crisis on Infinite Earths could be a possibility in this world, and it references Barry Allen’s heroic death as he tries to prevent the annihilation of countless other worlds. Barry Allen goes missing, but the red skies that so often symbolize the onset of a multiversal Crisis, vanish along with him. 

But as Gideon informs us a “time flux” causes a change, and that date now moves up five years, to 2019. Is this time flux a result of Nora’s meddling, the Cicada issue, Thawne’s return to our time, or something else entirely? That isn’t made clear. It’s the second episode in a row (after the Arrow season 7 finale) to overtly reference what should be the big fall crossover event, and it makes you wonder just how much of these shows’ upcoming seasons will be devoted to Crisis on Infinite Earths, rather than it being an isolated crossover event. But one thing is for certain… “World will live, worlds will die, and nothing will ever be the same.”

We’ll find out more when The Flash Season 6 arrives in October.

Mike Cecchini is the Editor in Chief of Den of Geek. You can read more of his work here. Follow him on Twitter @wayoutstuff.