Since the very first episode of The Flash, viewers knew that Barry Allen's (Grant Gustin) Flash would disappear from the time stream in the future. In a news article that Wells (Tom Cavanagh) had access to from the year 2024, a small image of The Flash could be seen, sporting his traditional colors from the comic books, with the headline, Flash Missing - Vanishes in Crisis.
In that same news article, there was a mention of a Wayne Tech and Queens Consolidate merger, which confirmed that Bruce Wayne does in fact exist in universe that The CW's Arrow and The Flash have been establishing.
With the recent announcement that The CW is developing a superhero team-up based on characters from Arrow and The Flash, one couldn't help but wonder if the Flarrowverse would one day introduce their version of The Justice League. That question won't remain a mystery for too long, thanks to Harrison Wells' trusty Artificial Consciousness, Gideon.
During the the final moments of "Who is Harrison Wells," Barry, Cisco (Carlos Valdes), and Caitlin (Daniel Panabaker) found themselves in Wells' secret lair, confirming once and for all that Wells is The Reverse Flash, and the one responsible for murdering Barry's mother.
Not only do they discover Wells' secret, but the trio also discover that Barry will go missing in about 9 years. What sort of repercussion this new information will have on Barry and the gang will have to be seen.
During next weeks episode, "The Trap," Barry and the gang will also meet Gideon. Gideon has served multiple purposes throughout the season, she has served as a link to the future, as well as offering advice on Wells' actions. The CW has released a promotional artwork featuring the encounter between the two parties and a very interesting conversation occurs.
Gideon essentially confirms that at some point from now till 2024, The Justice League would have already been formed. Not only that, but it does raise attention as to why Gideon hasn't referred to Wells as Eobard or Dr. Thawne. It could be to keep up the cover, but why keep the cover in a secret room? ...And why doesn't Gideon understand Barry's question?