Reign goes after her alter-ego’s family to kill off any resistance from Samantha Arias as the Legion of Superheroes plan their return to the future.

Previously, on SUPERGIRL

I’ve been expecting a variation on this episode since the split personality between Reign and Samantha Arias was introduced. At some point, the evil Worldkiller was going to go after Samantha’s daughter. I just wasn’t expecting the episode where it happened to be so jam-packed with other emotional beats.

This was a packed episode that advanced a lot of plot into an hour of television, with everyone but Winn getting a real character beat (though he did have a nice moment where Brainy gave him future dirt… that was rigged with a camera so Brainy could spy on the DEO). Reign hunting Samantha’s mother and daughter set up this week’s big action scene, while the other plots set up future conflicts. But, as is the case with the best ARROWVERSE episodes, everything came together at the end as the heroes found a way to contain the threat of Reign, who has now absorbed the powers of the other two fallen Worldkillers.

The most intriguing subplot is the growing tension between Supergirl and Lena Luthor over the Kryptonite Lena was using to keep Reign under control. Supergirl is upset that Lena has any of the deadly substance, and she feels even more betrayed when Lena admits that the Kryptonite didn’t belong to her brother Lex. Lena has discovered how to create her own Kryptonite. Even though she starts to distrust her former ally, Supergirl puts that behind her and takes Lena’s Kryptonite to help take down Reign, and finally apologizes towards the end of the episode. But during a random encounter between Lena and Kara (our first Kara sighting in quite some time), Lena admits that she no longer trusts Supergirl, noting the hero is not the person Lena thought she was.

The X-Factor here is James Olsen, who is now dating Lena. Last week, he lied to Kara about Lena’s stash of Kryptonite (which Lena tells Kara about later). Since the first season, the show has stressed that Olsen was a more suave, more mature version of the classically goofy character, though he seems to have the same weakness for women as his comic book counterpart. Considering his best friend is Superman, a guy who battled Lena’s brother frequently armed with Kryptonite, he doesn’t seem very bothered by Lena’s possession of the substance.

The tension between Lena and Supergirl should ramp up in the season’s final episodes, but I’m hoping it doesn’t result in Lena taking after her brother and becoming Supergirl’s arch-nemesis.

In other DEO team familial issues, the Legion prepares for a return to the 31st Century after defeating Pestilence, but Brainy’s insistence that Supergirl only has a 51 percent chance of defeating Reign weighs on Mon-El, especially after Brainy tells him that having one Legion member stand by her increases the odds into the 80s. Mon-El’s wife, Imra, tells him to head back and help, and he arrives just in time for the final battle with Reign, which takes place in Lex Luthor’s old mansion, where Lena stashed Sam’s daughter, Ruby. Lots of damage to no doubt priceless artifacts here. Lena’s Kryptonite is the tipping factor, as Mon-El crushes it down to a powder and uses one of Lex’s mounted weapons to shoot Reign with what are now essentially Kryptonite bullets. They take Reign back to the DEO and Lena gets to work trying to cure her friend.

Before the fight, though, we get another fun scene that calls back to classic Superman movies. As Reign is stalking through Lex’s mansion to find Ruby, she goes through an obstacle course of bullets, fire and ice that harkens back to a scene from the 1978 Superman movie (or, at least, a scene in the TV version of the film) where Kal-El went through similar challenges to get to Luthor’s underground headquarters. Little things like that are what I love about this show! That was the perfect cap to a really great episode.

With Reign subdued – again – it looks like we’re getting another break in the main action next week, as Olsen gets the spotlight, along with the return of the cult led by Thomas Coville.