“Did somebody call for backup? Because Colonel Haley stays ready!” jokes April Parker Jones, who started the season as Supergirl’s identity-seeking enemy and general DEO foe but ended as an ally. Jones’s favorite scenes to shoot? Action sequences, of course. “I love when it’s time to suit up and protect the DEO and the country,” she says.

Newcomer Nicole Maines (Nia Nal), here getting a touch-up, says she was like “a giddy kid” when she first suited up as Dreamer. Her biggest costume-related complaint? The vest is constructed to promote a super-stance at all times. “I’m not used to having such good posture!” Maines admits.

In just one season, Alex Danvers (Chyler Leigh, right) had her memories of sister Kara as Supergirl erased, took over the Department of Extra-Normal Operations (DEO) and embarked upon a slow-burn romance with James’s sister, Kelly (Azie Tesfai, left, in one of the first #Dansen scenes). “It’s been a great challenge for me to wear so many different hats,” Leigh says.

Katie McGrath’s L-Corp CEO Lena Luthor and Sam Witwer’s anti-alien agitator Ben Lockwood/Agent Liberty are both troublemakers in National City — but just try to find any villainy on Supergirl‘s Vancouver set. “I am still looking for the rotten core of this show because everyone has been so sweet and wonderful,” Witwer says, then adds with a laugh, “I intend to find out what’s wrong with them!”

Is Rath’s logical and lovable Legion of Super-Heroes member Brainiac 5 connected to Krypton‘s evil Brainiac? The shows are “in different universes,” explains Supergirl exec producer Jessica Queller, admitting that while the two Coluans do share a home planet and similar backstories, they’re not the same character.

David Harewood (left), aka Martian Manhunter J’onn J’onzz, made his directorial debut in Season 4. “American Dreamer” depicted James Olsen/Guardian (Mehcad Brooks, above) dealing with a childhood trauma by letting Brainy (Jesse Rath) dive into his mind. “Mehcad had a great arc that came to an emotional conclusion in this episode,” Harewood says. Plus, James uncovered a new skill: heat vision.

Melissa Benoist has portrayed Supergirl for four seasons now — and Jon Cryer, who swung by for a three-episode arc as iconic supervillain Lex Luthor, was impressed by her performance. “She just fulfills the role in a remarkable way,” he raves. “We had this one scene where she was in full costume and they hit her with the Beyoncé fan — I got chills.”

Saving aliens and showing newbie heroes the ropes takes work, so just imagine the efforts put in on and off screen by this team!

Click through the gallery above for a behind-the-scenes look at Supergirl Season 4, with insight from the cast and executive producer.

Supergirl, Season 5 Premiere, Sunday, October 6, 9/8c, The CW

For more exclusive content from your favorite shows like Arrow, Supergirl, and more, pick up TV Guide Magazine’s Special Comic-Con Issue, on sale now. It's an all-access SUPERFAN guide with 88 pages of behind-the scenes photos, scoops, and interviews.