It was revealed shortly before The Flash concluded its first season that Season 2 would explore alternate worlds within the show’s mutliverse, specifically Earth 2. This will allow the show to not only introduce new characters, but also alternate versions of people we got to know during Season 1. (Please let this be how they bring back Eddie Thawne.) While details are still scarce on how these alternate worlds will come into play, it sounds like fans will get to see Earth 2 a lot sooner than we expected.
Executive producer Andrew Kreisberg says that The Flash took great care in Season 1 to make time travel easy enough for regular viewers to understand and complex enough for the hardcore fans to enjoy. The showrunner assured viewers that the same care will be taken with parallel worlds, and teased fans that Earth 2 will be seen early in the season. According to EW, here's what Kreisberg said:
We’re trying to do the same thing this year with Earth 2 and the concept of the multiverse and the concept of dopplegangers. We’ve been having a lot of fun with that and getting glimpses of Earth 2 probably sooner than people would’ve thought.
In The Flash Season 1 finale, Barry Allen ran headfirst into the temporal singularity unleashed by him traveling back in time. We know he’s going to make it out of there okay, but what awaits him on the other side has been a mystery. The article notes that the singularity “leads to a pretty familiar place,” hinting that it may transport Barry to Earth 2, which may be similar to our Earth, but also has a lot of differences. So far, the only Earth 2 character that’s officially been confirmed is Golden Age Flash Jay Garrick (played by Teddy Sears), whose helmet was briefly seen in “Fast Enough.” Tom Cavanagh is remaining on the main cast as an alternate Harrison Wells, but it hasn’t been specified whether he will hail from Earth 2 or another Earth.
In the Season 2 premiere, Barry will go up against Atom Smasher (played by Adam Copeland), and it was mentioned in the character announcement that the entire S.T.A.R. Labs team would have to come together to help Barry defeat the super-strong metahuman. However, maybe this isn’t the S.T.A.R. Labs team we got to know in Season 1. Maybe this is the Earth 2 team that for some reason disbanded, and Barry has to bring them together to help him stop this menace. On the off-chance that isn’t the case, maybe Barry will end up back in his own universe when the show returns in the fall, and the Earth 2 glimpses will be characters from that universe somehow monitoring what’s happening on the show’s main Earth.
Whatever Earth we get to see first, The Flash Season 2 will debut on Tuesday, October 6 in its normal timeslot on The CW.