'The Flash': What Is Babel Protocol?

Tonight's episode of The Flash will contain a pretty sly DC Comics Easter egg - and we're here to tell you what it might mean.

Earlier this week, fans spotted a pretty noteworthy Easter egg hidden in the trailer for tonight's episode, 'Mixed Signals'. One of the options on Cisco's control screen for Barry's suit included "Babel Control" - something that will raise the eyebrows of DC Comics fans.

In the comics, Babel is most often associated with 'Tower of Babel', a 2000 Justice League of America storyline. It follows Batman keeping an index of records about his team-mates, including the various ways to neutralize them in a fight.

Unfortunately, these records get into the hands of Ra's al Ghul, who uses them in pretty dangerous ways. Aquaman suffocates after being rendered aquaphobic, Wonder Woman dies of exhaustion after being trapped in an endless virtual reality battle, and The Flash is hit with a "vibra bullet", which causes him to have a seizure at light speed.

Ultimately, the effects of these attacks aren't permanent, they just last long enough for R'as Al Ghul to enact his plan. But still, they have a pretty large impact on the team's heroes.

So, how could this be used in The Flash? It's safe to assume that Team Flash wouldn't outfit Barry's new suit with any sort of vibra bullet technology. But given Barry's recent return from the Speed Force, it wouldn't be too surprising for the protocol to be some sort of failsafe against an evil Barry. And if the protocol does have some sort of significant repercussions, it could be used against the Scarlet Speedster - especially by a villain like this season's Big Bad, The Thinker.

Fans will just have to wait until tonight's episode to see what happens with The Flash's Babel Protocol.

The Flash airs Tuesdays at 8/7c on The CW.