The Flash” Season 2 has been having a bit of fun with doppelgangers thanks to the introduction of parallel dimensions. Now, the superhero will be tested more than ever before as he travels to Earth-2 to rescue the doppelgangers of some of his best friends from the doppelgangers of some of his other best friends. (Yes, it's confusing, but stay with us.)

Last week’s episode saw Dr. Harrison Wells (Tom Cavanagh) finally reveal that he’s been working with the very scary universe-hopping villain Zoom. It would have been very easy to simply lock Wells up or exile him back in Earth-2, but Barry Allen (Grant Gustin) reminded his friends that they’re heroes. If they were to punish Wells, it would result in the death of his daughter, who is being held captive by Zoom. Instead, he proclaims that the time has come to take the fight to the evil speedster. As a result, episode 13 of Season 2 will see The Flash, Cisco (Carlos Valdes) and Wells take a trip to Earth-2 to rescue Zoom’s captive and, let’s face it, play around in a parallel dimension. Sadly, that leaves the burden on Jay (Teddy Sears) and those still on Earth-1 to pick up the slack.

“Barry, Wells and Cisco travel to Earth-2 to rescue Wells’ daughter from Zoom, and encounter Killer Frost and Deathstorm,” the episode’s official TV Guide plot synopsis reads. “Meanwhile, back on Earth-1, Jay takes over The Flash’s duties when a meta-human nicknamed Geomancer attacks Central City.”

While a new meta-human is always a scary thing to deal with, the real threat appears to be on Earth-2. In a teaser trailer for the new episode, the identity of Killer Frost and Deathstorm are revealed as the doppelgangers for Caitlin Snow (Danielle Panabaker) and returning guest character Ronnie Raymond (Robbie Amell).

The Flash "The Flash" Season 4, episode 13 will see the hero travel to Earth-2 and encounter the doppelgangers of his friends Caitlin Snow (Danielle Panabaker) and Ronnie Raymond (Robbie Amell). Photo: the CW

It’s unclear exactly how, but it seems like the Earth-2 equivalent of the particle accelerator that gave The Flash and so many others their superpowers also affected his Earth-2 friends. Particularly, Caitlin, who has no powers on Earth-1 is somehow a frost-powered femme fatale in the parallel dimension. It’s unclear if she’s married to Ronnie the way she is in Earth-1, but they’re definitely working together as villains, which will pose an awkward dilemma to Barry.

In addition to villainous friends, the teaser promises the introduction of doppelgangers for Barry, Iris (Candice Patton), Joe (Jesse L. Martin) and more. In the kickoff to this two-part event, the Earth-1 heroes will only have a limited time to stop the villains, rescue Wells' daughter, survive another onslaught from Zoom and get back to their world before the portal closes behind them forever. To see how it all gets started, fans will have to tune in to “The Flash” Season 2, episode 13 on Tuesday, Feb. 9 at 8 p.m. EST.