The 100th episode of The CW's Supergirl aired Sunday, and the anniversary was commemorated with appearances from several of the show's past characters. There were some notable omissions, however, but the episode's showrunners have explained why at least some of those potential appearances couldn't happen.
Absent from the centennial episode were Calista Flockhart, who played CatCo CEO Cat Grant in the show's first two seasons, as well as Mehcad Brooks, who more recently played James Olsen/Guardian. Co-showrunners Robert Rovner and Jessica Queller cited the actors' availability as the reason for their absence.
"It would have been lovely and wonderful if Calista could have been available to come back for it," Rovner said in an interview with ComicBook.com. "Mehcad was off shooting a movie so he wasn't available to come back for it."
"Yes. But we're so thrilled with the episode," Queller added. "And we were just crazy about Tom Lennon's performance and how buoyant and magical he is. And it's really one of our favorite all-time episodes." Lennon played Mr. Mxyzptlk in the episode, and the character served as the impetus for Supergirl to go back and revisit key moments in her relationship with Lena Luthor.
"And even without them being available, we wanted to make sure that they were a part of the episode," Rovner said. "And so, Calista is referenced in her image is in it, and the same with Mehcad, we've gone back to scenes with him."
Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter and Chyler Leigh as Alex Danvers.