The Flash season 6 ended with the Mirror Mistress undefeated and the overarching plot still unresolved, as a consequence of production being shut down before it was supposed to. What this means is that we’ve got months to theorize about what could happen next in Team Flash’s ongoing battle with Eva McCulloch. For one, we know that Iris is still stuck in the Mirrorverse. But what if she’s not the only one? What if Barry is, too, and the one we’ve been watching is really a duplicate?
That’s the wild idea this theory suggested by ScreenRant runs with, but there is actually a fair amount of evidence to back it up in the last few episodes of season 6. To start with, episode 19 “Success is Assured” saw Barry confronted with Mirror Singh who, on behalf of Eva, offered to release Iris if Team Flash let her kill her husband, Joseph Carver. The speedster hesitated in his reply before Nash teleported him out of the situation. Nash then berated Barry for not simply refusing the offer. He even pointed out that every Wells in his head was saying that the Barry they knew would never swap one life for another. Barry argued that anyone would do anything to save their loved one, but is that all there is to it?
Think back to episode 17 “Liberation” as well. When trying to prove Mirror Iris was a fake with a prismatic scanner, she managed to get the jump on him by switching the device for a mirror copy. When it was used, then, it read her as completely human but Barry as a mirror duplicate. This could have been the mirror scanner simply swapping the results, but it’s worth pointing out it was never tested on anyone else. Has Barry actually been a duplicate for weeks?
In the finale, Carver suggests that Eva isn’t really his wife, just a mirror copy that believes she is. If he’s right, then this could also be the case with this potential Mirror Barry. The twist that Iris was a fake was a great rug-pull moment, but revealing that the Flash himself has been replaced all this time would be an even bigger shock when the show returns next year for its seventh season.