DC Comics is about to have two versions of The Flash on screens. Gracing the big screen will be Ezra Miller in the title role. That film will come a week earlier than previously expected on March 16, 2018. On the small screen, the Flash is portrayed by Grant Gustin and remains one of The CW's most popular shows. Given the success of The Flash on The CW network, we will likely continue to see Grant Gustin in the role through 2018 (when the film debuts) and beyond.
Season 2 of The Flash has introduced the concept of the multiverse with Earth-2, a slightly altered version of Earth-1 where Barry Allen (Grant Gustin) is from. Introducing alternate dimensions and alternate timelines has led to some pretty crazy plot threads, and we're likely to see some more in the near future, as Team Flash makes an inter-dimensional jump to see just how different things are on Earth-2.
Now TVLine reports that another member of the rogues' gallery may return to The Flash soon. The Pied Piper (as portrayed by Andy Mientus) is set to appear in the season 2 episode 'Flash Back'. But there is more to it than a simple visit from a familiar villain, as it was also reported that The Flash will encounter the Pied Piper when he "revisits an earlier timeline."
Pied Piper (a.k.a. Hartley Rathaway) is a metahuman with ultra-sensitive hearing, and sonic technology that previously threatened the crew of S.T.A.R. Labs. He was involved in the search for Ronnie Raymond (Robbie Amell) in season 1, before it was known that Raymond had bonded with Professor Stein (Victor Garber). Rathaway eventually found a way to escape the "Pipeline" -- the makeshift jail for metahumans assembled in the ruins of machine that spawned so many super powered individuals. Ronnie Raymond eventually died for good (we think), but Robbie Amell will also make a return to the show via an alternate dimension, as the villainous character Deathstorm.
But just because Pied Piper escaped in season 1 that doesn't mean that this particular version of the character will be the same. After all, the report mentions an "earlier timeline." The Flash has already approached concepts like time travel and the multiverse, with some success. Barry Allen has also gone back in time to change the past on a few occasions. It's likely that we'll see Andy Mientus return as the Pied Piper in a similar scenario. It will be interesting to see when and how the character will return, as he had a huge effect on core characters (like Cisco) during his brief appearance during season 1.
The Flash returns tonight with ‘Welcome to Earth-2′ at 8pm on The CW.