After a month-long holiday hiatus, The Flash is getting ready to return with its first 2016 episode, Potential Energy, airing tomorrow, Tuesday, January 19 at 8 PM ET on The CW. While we wait for this new episode to arrive, The CW Network has released an extended trailer for the back half of Season 2, which teases the Earth-2 Firestorm (Robbie Amell) and his girlfriend Killer Frost (Danielle Panabaker). This footage also gives us another look at Jay Garrick (Teddy Sears) and Wally West (Keiynan Lonsdale).

The Flash Season 2 introduced a new villain to Central City, Zoom, who is voiced by Tony Todd. The show's producers have teased that fans won't know who is truly know who is inside the Zoom suit until the end of this season. Some fans have speculated that Zoom could be the Earth-2 version of Barry Allen, but series star Grant Gustin doesn't think that is the case. Here's what he had to say in a new interview with Comic Book Movie.

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"I don't think it's going to be Evil Barry. But I was pitching that idea really early on, like, 'How fun would that be, it'd be so cool!' I just selfishly wanted to play the villain. I didn't even know who it was until last night, actually. I hadn't asked. I asked way more questions last year. Jesse [L. Martin] likes to know as little as possible and I'm kind of taking that route this yea, so I'm surprised when I see the scripts and surprised when I do it. I hadn't asked who Zoom was. I didn't want to know, but [Greg] Berlanti called me last night to catch up and talk about the episodes and that came up and he broke down that whole story for me and how it's going to evolve and what's going to happen. So I do know now. Obviously, I'm not going to tell you! [Laughs] There are so many twists and turns involved with it and so many characters' arcs that are connected to it. I said it about Thawne last year. Even if you think you know, there's going to be."

What we do know about Zoom thus far is that he is from Earth-2 and he has speed that matches or even surpasses Barry Allen's. We have already seen how different versions of Earth-2 characters are from their Earth-1 counterparts, including Tom Cavanagh's Harrison Wells, who will play a big part in the back half of this season. Here's what executive producer Andrew Kreisberg had to say in a separate interview with Comic Book Movie, teasing that Team Flash will be taking the fight to Zoom in Earth-2.

"At some point, they're going to decide to take the fight to Zoom. Some of these [Earth-2 doppelgangers] are beyond different. What's so interesting is that you've got Wells, who is probably the most similar to himself - the one that we saw last year and this one. They seem different until you start seeing the crazy differences between all of our other cast members. Then he's the one who doesn't seem quite so different and crazy anymore. We've obviously announced Robbie Amell and you've seen the photos of Danielle Panabaker as Killer Frost, but there's a couple of surprises that we've got in store that we're really excited about."

The network also recently announced that filmmaker Kevin Smith has come aboard to direct an unspecified episode of The Flash at some point this season. Directly following tomorrow night's midseason premiere is a new special DC's Legends of Tomorrow: Their Time Is Now, which offers new insight into the series DC's Legends of Tomorrow before it debuts on Thursday, January 21. Take a look at the new extended trailer for The Flash, before tuning in tomorrow night.