Only on The CW, Supergirl Season 2 continues tomorrow night with the episode We Can Be Heroes. But series star David Harewood is much more excited about next week's episode, as he revealed a new poster for The Martian Chronicles, which premieres February 6. Melissa Benoist's Supergirl and David Harewood's J'onn J'onzz will reunite, with the poster tagline reading 'Worlds Clash, Heroes Unite'. Harewood shared this about the episode.

"The Martian Chronicles. Coming soon on the CW. Some lovely scenes with @sharonleal17 and some great writing. Looking forward to seeing the finished product."

The poster debuted on David Harewood's Instagram, but he wouldn't offer any further details on social media. The full synopsis was later released by The CW, and it reveals that there is another white martian living on earth. The episode is directed by David McWhirter from a script written by Gabriel Llanas and Anna Musky-Goldwyn.

"A White Martian named Armek (Terrell Tilford) arrives in National City to take M'gann (Sharon Leal) back to their home planet to face her punishment as a traitor. To keep M'gann safe, Supergirl and J'onn, a.k.a. Martian Manhunter, bring her to the DEO. Things, however, get tricky when they find out that Armek shape-shifted into M'gann. With the DEO's security compromised, the team realizes that Armek could be disguised as any of them."

As for tomorrow night's episode, a full synopsis has been released. And it sounds like Livewire's back for a little fun in We Can Be Heroes.

"After Livewire (guest star Brit Morgan) seemingly breaks out of prison, Supergirl is intent on recapturing her. After training Mon-El, Supergirl takes him with her when she sees Livewire attack the NCPD but things go awry when Mon-El puts Supergirl before the citizens of National City. Meanwhile, James decides to come clean with Kara and M'Gann (guest star Sharon Leal), has a psychic attack and collapses into a coma."

Based on the DC character, Supergirl, a.k.a. Kara Zor-El (Melissa Benoist), decides to embrace her superhuman abilities and become the hero who she was always meant to be on The CW series, Supergirl. When she was 12 years old, Kara Zor-El escaped the doomed planet Krypton and was sent to earth where she was protected and raised by her foster parents, Jeremiah (Dean Cain) and Eliza Danvers (Helen Slater) and her foster sister, Alex (Chyler Leigh). Under their supervision, Kara learned to conceal the phenomenal powers she shares with her famous cousin, Superman, in order to keep her identity a secret.

Years later, Kara was living a "normal" life in National City, assisting media mogul and fierce taskmaster Cat Grant (Calista Flockhart) and working beside her friend and IT technician Winslow "Winn" Schott (Jeremy L. Jordan) and famous photographer James Olsen (Mehcad Brooks), who Grant hired away from Metropolis's Daily Planet. When Alex's life was threatened in a plane crash, Kara took to the sky to rescue her. In the aftermath, Kara decided she could no longer sit on the sidelines and came out as Supergirl. She now balances her job at CatCo with her work at the Department of Extra-Normal Operations (DEO), a super-secret government agency where Alex also works. At first, the head of the DEO, Hank Henshaw (David Harewood), was resistant to Supergirl joining the DEO, until it was revealed that Hank was actually J'onn J'onzz, the Martian Manhunter, who had promised Jeremiah Danvers on his deathbed that he would protect both Alex and Kara.

It has since been discovered that Jeremiah is actually alive and being held by Cadmus, a dangerous quasi-military organization that sees all aliens as threats. In Season One, Supergirl soared fighting crime and battling various villains, chief among them two Kryptonians who were intent on destroying earth, but she has yet to find that same empowerment as Kara Danvers. Now, in The CW's Supergirl Season Two, Kara has left the safety of being Cat Grant's assistant in order to figure out what she really wants to do, while as Supergirl she continues to work at the DEO, protecting the citizens of National City and searching for Jeremiah and Cadmus. Along the way, she will team up with Superman (Tyler Hoechlin) to battle new villains, as she strives to balance her personal life with her life as a superhero.

The hit series will be introducing a number of new characters this season, including Lynda Carter, the original Wonder Woman, as the President of the United States. Floriana Lima has also signed on to play Maggie Sawyer, the first ever openly gay comic book character, with the show also introducing her girlfriend Kate Kane (Batwoman), and Barbara Gordon (Oracle). While we wait for tomorrow's episode of Supergirl to air on The CW, take a look at this new poster below.