Warning: Spoilers Ahead for tonight's episode of The Flash, titled "The Race of His Life."

Tonight on The Flash, Barry finally had his final confrontation with Zoom and managed to save the multiverse from imminent destruction.

After that, thought, distraught by his failure to save his father and the betrayal he suffered at the hands of his friends, Barry traveled back to the past and saved his mother from being murdered by the Reverse-Flash.

In the comics, a storyline with a similar starting point -- Flashpoint -- ended up changing time, merging the DC Universe with longtime Vertigo presences like Swamp Thing and Constantine, and bringing the Wildstorm universe into continuity as well.

On The Flash, there's really only one alternate earth that would make sense to merge into the "main" continuity -- that of Supergirl, the former CBS show that's headed to The CW in the fall.

Of course, when The Flash visited Supergirl's National City this season, it was by way of a breach that carried him to an as-yet-unmapped alternate Earth.

Could a Flashpoint-style realignment of space and time bring National City and the Last Daughter of Krypton to Earth-1?

Usually, the obvious answer would be no: the move would fundamentally alter another show, and it wouldn't make sense to cede that much creative control to Team Flash. But if it meant making Supergirl work better within the context of the shared universe with the other CW shows, there might be a compelling argument that it's a good idea.

Certainly, that would make the planned four-way crossover between Supergirl, The Flash, Arrow, and DC's Legends of Tomorrow easier to manage. And if they were to move just National City while keeping the rest of Supergirl's Earth as-is, it could mean that Supergirl no longer has to answer the "where's Superman?" question every time there's a big story going on.

Is it likely? Probably not...but it's certainly worth thinking about, at least in that fan-conspiracy-theory kind of way.