Check out new Supergirl season 4 photos

Up, up, and away! In season 4 of Supergirl, Kara (Melissa Benoist) will have her hands full dealing with Agent Liberty (Sam Witwer) and her doppelgänger who landed in Russia at the end of season 3, while also mentoring Nia (Nicole Maines), CatCo's newest reporter. Click through to see every new image from the new season.

Supergirl airs Sundays at 8 p.m. on the CW.

Willie Garson as Steve

Here's the logline for the episode:

"Supergirl (Melissa Benoist) must deal with the destructive aftermath of Lex’s (guest star Jon Cryer) nefarious plans. Shocked at what Lex has created, Supergirl faces her biggest challenge yet."

Prepare to find out how Lex Luthor (Jon Cryer) is connected to Red Daughter (Melissa Benoist).

“In some ways, I am relating to Supergirl, but it’s a Kasnian version of Supergirl, and it’s fun,” Cryer said about the scenes he shares with Benoist as Red Daughter. “It’s really fun to play with that relationship because it’s so different."

“She’s masterful, and you’ll see the character is so different from the character of Kara, and so it’s remarkable,” said showrunner Jessica Queller about Benoist's performance. “You’ll see the whole origin story of Red Daughter.”

Here's the official logline:

"In the wake of Lex Luthor’s (guest star Jon Cryer) return, the show flashes back to what he’s been doing for the last two years and how his secret machinations and plans have affected Supergirl (Melissa Benoist) and Lena (Katie McGrath)."

Azie Tesfai as Kelly Olsen

Here's the logline:

"Secretly furloughed from prison due to failing health, Lex Luthor (guest star Jon Cryer) visits his sister, Lena (Katie McGrath), to seek her help finding a cure. Savvy as ever, Lena is suspicious of Lex’s motives but when she’s faced with a life and death situation, she must decide how she truly feels about her brother. Meanwhile, Supergirl (Melissa Benoist) and J’onn (David Harewood) face off against Manchester Black (guest star David Ajala). James’ sister Kelly (guest star Azie Tesfai) comes to town."

Jon Cryer makes his debut as Lex Luthor.

"I think that he’s the biggest supervillain we’ve had the show, and his plans will kind of touch every character and impact the entire season moving forward once he arrives," EP/co-showrunner Robert Rovner previously told EW, with EP/co-showrunner Jessica Queller adding, "He just [has] a sparkle in his eye and is smarter than everybody in the room and 12 steps ahead of everyone, and just a large, delicious villain.: