Adrian Pasdar as Morgan Edge, Katie McGrath as Lena Luthor, Melissa Benoist as Kara Danvers
Kara (Melissa Benoist) stands up for her best friend Lena (Katie McGrath) when Morgan Edge tries to ruin her reputation in Season 3, episode 5 of “Supergirl.” The CW

Next week’s Season 3, episode 5 of “Supergirl” may mark the start of Lena Luthor’s descent into the dark side.

As previously reported, Morgan Edge (Adrian Pasdar) blames Lena (Katie McGrath) when multiple children get sick from lead poisoning in the episode. Morgan claims that the children’s lead poisoning is caused by the lead bomb Lena created to save National City from the Daxamites last season. Kara Danvers (Melissa Benoist) and Samantha Arias (Odette Annable) try to clear Lena’s name. But before they can resolve the issue, it seems that Morgan’s allegations have already triggered the L-Corp CEO’s dark side.

“Kara is willing and ready to stand up for her best friend by any means possible,” Benoist told Entertainment Weekly. “[But] Lena’s maybe [on a] slippery slope onto what you could sadly call her birthright. I don’t know for sure, but it is a fragile balance beam that Kara and Lena are walking on, these two as friends in the way that Lex and Superman (Tyler Hoechlin) had.”

In the trailer for the episode, Lena seemingly takes the matter into her own hands. During a meeting with Morgan, the new owner of CatCo Worldwide Media pulls out a gun and points it to the real estate developer. But in an unexpected turn of events, Lena ends up being the one who needs saving. At the end of the promo clip, Lex’s sister appears to be in an aircraft that is about to crash.

The episode was directed by Kevin Smith — the same guy who directed “Supergirl’s” “Supergirl Lives” and “Distant Sun” episodes last season. In an interview with Screen Rant at last month’s New York Comic Con, Smith explained how his third directorial episode on “Supergirl” differs from his previous two episodes.

“It didn’t have a comic book villain to speak of,” Smith said of episode 5. “But, you know, of course, every episode there’s a threat that Supergirl has gotta deal with and stuff, this one’s just not ripped from the pages of the comics. The first two I did on ‘Supergirl’ were very space oriented. This one [is] very Earthbound. This season of Supergirl seems to be more grounded. Not that she’s not flying, but just—less space, more Earth.”

“Supergirl” Season 2, episode 5, titled “Damage,” airs on Monday, Nov. 6 at 8 p.m. EDT on The CW.