Warning: spoilers ahead for the penultimate episode of The Flash Season 4, called "Think Fast."
Only one episode is left in The Flash Season 4, and "Think Fast" just set Team Flash up for a major crisis in the finale. The Thinker managed to pull off his plan to start his Enlightenment, using STAR Labs' satellite along with other satellites to kick off the process that, unless stopped, will result in the vast majority of humanity having their minds wiped. Now, Team Flash has a few irons in the fire that could come in handy in saving humanity before The Thinker destroys their minds next week, and the fact that all the shows of the Arrow-verse scored renewals means that we don't have to worry that The Thinker will indeed affect the entire population of Earth-1, but there are reasons to believe that the Enlightenment could result in permanent damage to the Arrow-verse as a whole.
The Flash hasn't held back on plots that result in changes that impact the entire superhero universe on The CW. Barry's decision to run back in time and kick off the disastrous Flashpoint timeline resulted in everything from the death of Cisco's brother on The Flash the Diggle's daughter being switched out for a son over on Arrow, and there was damage that could not be undone. The Enlightenment could very well be on the same scale as Flashpoint, and the changes could be permanent. Will everybody in the Arrow-verse have their minds wiped? Certainly not. Is there a potential for permanent damage? Absolutely.
Admittedly, this isn't the first time that one of the Arrow-verse shows has gone so big that fans have to wonder why the titular heroes aren't calling on their pals from the other shows. Oliver and Barry have spent years dealing with respective crises in their own cities around the same time. The Flash and Arrow couldn't do anything to fundamentally change the other show as long as they aired their finales in the same week. This time, the finale air dates could be a clue that The Flash is going above and beyond to mess things up for everybody.
For the first time since The Flash Season 1, its finale will not air in the same week as one of the other Arrow-verse shows. The Flash's Season 4 finale will hit the airwaves on May 22, which is after this week's Arrow finale and well after the Legends of Tomorrow back in early April. (Supergirl will still be going, but Supergirl is set on Earth-38, meaning that Team Flash's conflict with The Thinker likely won't affect Kara and Co.) The Flash can theoretically do just about anything to the Arrow-verse in its finale without messing things up for the finale arcs of any other shows.
Unlike Team Arrow's issues with Ricardo Diaz over in Star City, Team Flash's issues with The Thinker are on a global scale, and The Thinker has already kicked off the Enlightenment. At least some damage is presumably already done. Unless Team Flash is able to set everything right by the end of the Season 4 finale -- which will reportedly end on two cliffhangers -- permanent changes are almost certainly in store. After all, even the brain trust that is Team Flash hasn't been able to figure out exactly how to restore Harry's intelligence; isn't it possible that they won't be able to restore many other people who will be affected by the Enlightenment as well?
We'll have to wait and see. Perhaps The Flash's finale airing last of the Earth-1 Arrow-verse shows is just a fluke of CW scheduling and the good guys of The Flash will be able to fix absolutely everything by the end of the finale. Iris did seem to make some progress on recruiting Marlize to help battle The Thinker, and Caitlin went on a blast from the past that indicated her Killer Frost persona was always within her and not at all the result of a particle accelerator explosion. Assuming The Flash stays on Tuesday nights at 8 p.m. in the 2018-2019 season, it will also premiere first of the Arrow-verse shows set on Earth-1. Any kind of cliffhanger is possible at this point. Personally, my fingers are crossed that whatever happens, Mystery Girl is involved. We deserve to know more about her before hiatus!
Tune in to The CW on Tuesday, May 22 at 8 p.m. ET for the Season 4 finale of The Flash. Our superhero TV guide can point you toward more comic book characters on the small screen, and our summer TV premiere schedule can help you decide what to watch while The Flash and the rest of the Arrow-verse shows are on hiatus.