CBS Supergirl casts Dean Cain in recurring role as Jeremiah Danvers
Actor Dean Cain arrives at the 11th season finale of "American Idol" in Los Angeles, California, May 23, 2012. Reuters/Jason Redmond

“Supergirl” (Melissa Benoist) is considering sharing her secret with another character, according to the CBS episode guide. Meanwhile, viewers will get to see Dean Cain and Italia Ricci again in the next new episode. Watch the promo video here.

Spoiler alert: This update contains “Supergirl” spoilers. Read on if you want to find out what happens next to the “Supergirl” cast and characters.

The audience learned in Episode 16 (“Falling” original air date: March 14 on CBS) that National City now sees its own superhero as a threat. This is the result of the failed Red Kryptonite experiment ran by Maxwell Lord (Peter Facinelli).

Quick review: The Red Kryptonite altered the brain of Kara Danvers, allowing Melissa Benoist to play mean girl and show off unseen depths of her acting prowess. The “Glee” alum can play it nice and evil; she can be dark or “adorkable” depending on what’s required. When Kara confronts Cat Grant (Calista Flockhart) to show her that #PowerIsPower, she saw a side of her that could rival Cersei Lannister of “Game of Thrones.” (Watch the reference GOT video clip here.)

Here’s what happened when Kara Danvers lost it and showed Cat Grant that #PowerIsPower

Kara regains her senses toward the end of Episode 16, thanks to Maxwell for coming up with some sort of an antidote to his Red Kryptonite. The first order of business for Supergirl is apologise to people she has hurt. Alex (Chyler Leigh) assures her no love is lost, but they have things to work out. James Olsen (Mehcad Brooks) stops her when she tries to tell him that she loves her, but she got to say that she was jealous of Lucy Lane (Jenna Dewan Tatum), who seems to have left National City.

The next new episode (“Manhunt” original air date: March 21 on CBS) takes the viewers some years back, when Hank Henshaw (David Harewood) was on a Peruvian mission with Supergirl’s adoptive father, Jeremiah Danvers (Dean Cain). This flashback connects to the Episode 16 development, in which J'onn J'onzz a.k.a. Martian Manhunter revealed himself to DEO.

Kara Danvers is considering revealing her real identity to another character. Could it be Cat Grant? In previous episodes, Cat was sure Kara is Supergirl. This certainty was shaken when J'onn J'onzz morphed into Supergirl so they could both face Cat at the same time. However, Cat should be able to connect the mean "Kiara" to the "sick" Supergirl in the latest episode.

Siobhan Smythe (Italia Ricci) gets to shine as an emerging villain in the next episode. Her alter ego, DC Comics’ Silver Banshee, is set to unravel. Kara in her mean girl mode is the reason why Siobhan lost her job at Cat Co. Now, she wants revenge. In Episode 18, she even teams up with Livewire (Brit Morgan).

Episode 18 is the “Supergirl” crossover episode with Barry Allen a.k.a. The Flash (Grant Gustin). Fans of “Glee” could barely wait for this special episode which the fans themselves demanded soon after seeing the pilot episode of “Supergirl.”

Both Melissa Benoist and Grant Gustin starred in the now defunct Fox comedy musical “Glee.” Their characters are both adorable and geeky, and both actors make good family drama with their co-stars.

WATCH: Supergirl 1x17, Manhunter Promo Video (CBS on YouTube)