[This is a review of Supergirl season 2, episode 17. There will be SPOILERS.]

In season 2 of Supergirl, the show featured a marked shift from its focus on Kara Danvers' day job at CatCo to her extracurricular activities as the series' titular superhero. Along with this shift, season 2 has explored many aspects of aliens living publicly on Earth as refugees of their home planets. While many of this season's episodes featured the anti-alien organization Cadmus - lead by Lillian Luthor (Brenda Strong) - as Supergirl's main antagonist, last week's episode, 'Star-Crossed', introduced a new element to the show.

The Daxamite Mon-El landed on Earth in the season 1 finale - though he wasn't revealed until the season 2 premiere - and we've followed his integration to life in National City, working with the DEO, and growing closer to Kara despite her anti-Daxamite prejudices (and his anti-Kryptonian prejudices). However, 'Star-Crossed' saw the arrival of his parents, Rhea (Teri Hatcher) and Lar Gand (Kevin Sorbo), as well as the revelation that Mon-El is the prince of Daxam. Now, after Kara seemingly forgave Mon-El for lying to her in Supergirl's musical crossover with The Flash, the Girl of Steel has a new problem to sort out.

This week's Supergirl, 'Distant Sun' features the return of Kevin Smith as director - for the episode written by Gabriel Llanas and Anna Musky-Goldwyn - as a bounty is put out on Kara, forcing her to face off against all those who would want to collect on it. Meanwhile, J'onn J'onzz gets an order from President Olivia Marsdin (Lynda Carter), and Alex and Maggie run into the latter's ex-girlfriend.

Kevin Smith's Triumphant Return

Melissa Benoist and Kevin Smith pose together for Supergirl

With the debut of 'Distant Sun', Smith has directed a total of four episodes within The CW's shared DC Comics television universe: two of The Flash, and now two of Supergirl. His work on The Flash - season 2's 'The Runaway Dinosaur' and season 3's 'Killer Frost' - has been well received by critics and fans alike for combining comic book fun with the show's emotional weight, and he has achieved the same on Supergirl. That said, Supergirl is somewhat lighter in nature and tone than The Flash - especially as of late with Barry Allen (Grant Gustin) walking an incredibly dark path this year - and that bit of difference allows Smith to flourish.

Undoubtedly, 'Distant Sun' wouldn't work quite as well without the particularly upbeat and reference-heavy script from Llanas and Musky-Goldwyn. In fact, whether at Smith's request, the writers' desire to play to the director's strengths, or simple coincidence, 'Distant Sun' features quite a bit more direct references to DC Comics. The episode's inclusion of Kara being called the Girl of Steel and the Last Daughter of Krypton, as well as the various alien villains, combined with Smith's energetic directing makes for an altogether fun experience that feels wholly inspired by the comics - and is more entertaining for it.

'Distant Sun' isn't entirely an upbeat, conflict-free episode though, as both Kara and Mon-El carry the emotional weight of the main storyline. While Mon-El must face the fact that his mother would put a bounty on his girlfriend's head to ensure he returns to Daxam, Kara is forced to lay low when it goes against her nature to ignore those in need. Then, of course, she must deal with Rhea's determination to get Mon-El back by any means necessary. Kara's fight against Rhea while the Daxam queen wielded a Kryptonite dagger in the Fortress of Solitude offered an emotional weight, which Melissa Benoist was able to double down on in the following scene in which Supergirl pleaded with J'onn to allow her to rescue Mon-El.

Beyond the comic book references, the episode featured a direct connection to Smith's last foray as director on Supergirl - the midseason premiere 'Supergirl Lives' - through the teleporter that the DEO confiscated from the human/alien trafficking ring. The teleporter is used in a particularly entertaining climactic battle sequence aboard Rhea and Lar Gand's spaceship. But, while it appears as though Kara and Mon-El are eventually able to make headway with his parents, Rhea pulls a somewhat predictable backstab - or should we say gut-stab?

Rhea Goes Full Villain

Hatcher's Queen Rhea has been a terrifying force since debuting on Supergirl just two episodes prior to 'Distant Sun', but the actress is able to truly let loose this week episode as her character goes from helicopter mom to full blown villain. Rhea's arc is campy - bordering on cartoonish - with little actual time given to diving into reasons for her actions. Ostensibly, she's a mother willing to go to extremes for what she believes is best for her son, but as Mon-El points out, her underlying motivator is a need for control - the same control that lead to the oppressive nature of Daxam he hinted at in last week's episode.

Of course, control and power as the ultimate motivator for a villain isn't necessarily new ground, especially for comic book media. As such, Rhea deciding to murder her husband for allowing Mon-El to make the decision to stay on Earth isn't quite as surprising as the moment is played to be. The set up - an embrace that hides the murderer's intentions - is a classic image in film and TV and 'Distant Sun' doesn't do enough to differentiate the moment to avoid its cliche.

Still, with Rhea now having given up all pretenses of playing nice with either Kara or Mon-El, it remains to be seen what the Daxam queen can manage even with only a single spaceship worth of resources. Her ominous comment about not being done with Earth certainly sets the stage for a bigger battle between her and the Girl of Steel - one that will likely cause an intergalactic incident.

Who Is Olivia Marsdin?

Supergirl Lynda Carter Olivia Marsdin

Earlier in season 2, Lynda Carter guest starred in 'Welcome to Earth' as President Olivia Marsdin whose amnesty legislation helped establish the dynamics of humans and aliens in Supergirl. But, perhaps more intriguing, it was revealed in the final moments of the episode that Marsdin herself is an alien. Now in 'Distant Sun', the president uses her authority over the DEO to order that J'onn not engage with the Daxam spaceship so as not to provoke an attack on Earth.

Of course, since Rhea manipulates Mon-El onto the ship, Kara pushes J'onn to ignore the president's order and they engage with the Daxam force, seemingly winning the day. But, President Marsdin is unhappy with J'onn disobeying her order and promises there will be consequences - which will likely connect to whatever her own agenda may be as an alien masquerading as a human.

Though it initially appeared Carter would only appear in Supergirl season 2 as a one-off guest star, it seems the series is building to a reveal that could have massive consequences in Kara's world. With Carter's Marsdin at the center of it all, the mystery surrounding her character and her plans for Queen Rhea and Kara remain to be seen. As Supergirl gets closer to its season 2 finale, the show has quite a few balls up in the air. While they each pertain to the recurring theme of aliens in Kara Danvers' world, it's unclear how Supergirl will bring it all together in its final run of season 2 episodes.

Next: Should Supergirl & The Flash Do Another Musical Crossover?

Supergirl continues Monday, April 24 with ‘Ace Reporter’ at 8pm on The CW.