[This is a review of Supergirl season 2, episode 16. There will be SPOILERS.]

While the first season of Supergirl focused on Kara Danvers working to balance her life as a superhero with her job and relationships, season 2 has dealt with the theme of aliens facing prejudice as refugees on Earth -- in National City specifically. This theme has most obviously manifested in the season 2 villain, the anti-alien organization Cadmus led by Lillian Luthor (Brenda Strong), but it was additionally explored in the early episodes as Kara was forced to confront her own Krypton-born prejudices against Daxamites after the arrival of Mon-El.

For his part, Mon-El crash landed on Earth in a Kryptonian pod in the season 1 finale, and explained to Kara that he was a palace guard on Daxam who escaped prior to the planet's destruction. The pair have since become close and started dating, but in the midseason finale it was revealed a spaceship was pursuing Mon-El across the galaxy. Fans speculated Mon-El was the prince of Daxam, meaning he lied to Kara about his life on Daxam. That has since been confirmed, and the revelation proves to throw a wrench in his relationship with Kara - as well as introduce a new, alien villain to Supergirl

In this week's episode, 'Star-Crossed' -- written by Katie Rose Rogers and Jess Kardos and directed by John Medlen - Rhea (Teri Hatcher) and Lar Gand (Kevin Sorbo) arrive on Earth, completing their search for Mon-El. Meanwhile, Winn's girlfriend Lyra (Tamzin Merchant) gets him in trouble with the law, and he turns to Alex's girlfriend Maggie (Floriana Lima) for help. Plus, the episode introduces Music Meister (Darren Criss), setting the stage for Supergirl's musical crossover with The Flash.

Lyra Steals Winn's Heart

Despite the rather massive revelation dropped by Rhea and Lar Gand's arrival, Kara learning Mon-El's true identity isn't the main focus of 'Star-Crossed'. Rather, the episode shines a light on Winn and Lyra's budding relationship - into which a "Starry Night"-sized wrench is thrown. After helping Lyra break into a National City museum for what Winn thinks is simple fun, he's called into the police station by Maggie. It's quickly revealed Lyra used Winn to steal Van Gogh's "Starry Night" and set him up to take the fall - Maggie even reveals Lyra has done this to two other men.

Winn, with the help of Alex and James/Guardian, tracks down Lyra for answers in a storyline that mirrors Kara's in a lot of ways, but is largely kept separate from the Girl of Steel's own relationship turmoil - though the pair do share a moment of commiseration when it comes to having blind spots where the people closest to them are concerned. When Winn finds Lyra, however, the problem gets trickier as it turns out Lyra isn't the only Valerian from Starhaven stranded on Earth; she has a brother, Bastian, and he's captured by a gang that holds him hostage until she gives them the painting, which she was originally going to use to pay off her brother's debt to the gang. With the help of Winn, Guardian, Alex, and the DEO, Lyra is able to get her brother back and since they helped capture the leader of an art smuggling ring, they're free to go.

'Star-Crossed' ends with Winn forgiving Lyra for lying to him, since she betrayed him in order to save her brother. Winn speaks to Kara about understanding why Lyra lied - though it remains to be seen whether Winn and Lyra will remain together as that was left a bit open ended. Since previous episodes of Supergirl haven't spent too much time with Winn and Lyra, 'Star-Crossed' gives viewers the best insight into their relationship yet, even as it only scratches the surface of Lyra's life as a refugee. It's certainly compelling enough to carry the episode, and Jordan is able to pull off both Winn's typical humor and the chance to dig deeper into the character's emotions. Plus, the storyline gives Kara a bit of a break from the spotlight, while still informing the other storyline in 'Star-Crossed'.

Make Daxam Great Again

The arrival of Rhea and Lar Gand has been teased for the entire back half of Supergirl season 2 - not to mention the many hints at Mon-El's true role on Daxam prior to his escape - so the amount of attention paid to the Daxamite King and Queen is understated, and a little underwhelming. Certainly, Kara's initial recon of the ship provides for some exciting visuals, particularly her bursting from bubble-like trap and landing on a street of National City. Plus, based on Kara's initial dinner with Rhea and Lar Gand, as well as her conversation with Mon-El's mother, there's plenty of potential for episodes to come.

The conflict between Daxam and Krypton is rife with compelling drama, some of which was briefly explored early in season 2 through Kara and Mon-El, but Rhea and Lar Gand are more entrenched in their anti-Krypton prejudices, as well as their way of life with which Kara takes issue. Kara explaining to Alex that Daxam was kept oppressed by its rulers through their society's party culture, and Rhea's manipulation of Kara to drive a wedge further into her relationship with Mon-El, sets the stage for a compelling alien villain in the new Daxamite arrivals.

However, for the majority of 'Star-Crossed', Rhea and Lar Gand act as a measuring stick for how much Mon-El has changed since he first arrived on Earth. In the early episodes of season 2, he wasn't much better than his parents - drinking with Winn, not taking Kara or the DEO seriously. But 'Star-Crossed' makes a point of showcasing how different Mon-El is now. He refuses his parents' demand that he return to Daxam to help their people, choosing to stay on Earth with Kara because she makes him a better person (and, if we're being honest, he's still learning in that regard).

Still, while Winn could forgive Lyra her lies since they were an effort to protect herself and her brother, Kara recognizes that Mon-El's lies were selfish in nature. Prior to confronting his parents, Mon-El confesses to Kara that he's in love with her, but since she cannot forgive him, she breaks off their relationship. Things are tense at the DEO the next day, but a new prisoner mixes things up a bit.

Enter: Music Meister

The Flash/ Supergirl

Technically, the Supergirl and The Flash musical crossover only takes place in the latter's episode, 'Duet', but that didn't stop the writers of 'Star-Crossed' to set the stage. Not only does Music Meister make his grand entrance - complete with a daring escape to Earth-1 - the episode features a number of musical references. 'Star-Crossed' opens with Kara and Mon-El spending a night in watching Game of Thrones when the Daxamite suggests they watch a musical, prompting Kara to gush about her favorite: Fred Astaire and Audrey Hepburn's Funny Face. Plus, Lin-Manuel Miranda's blockbuster musical Hamilton is mentioned - with the added fun revelation that King George in National City's production is played by an alien - and Winn tells Lyra he "was a theater geek not a track star," in a reference to Jordan's own history in musical theater.

Aside from the small jokes and references sprinkled throughout 'Star-Crossed', the episode most obviously sets up 'Duet' with the introduction of Criss as Music Meister. His scene is brief, but undoubtedly entertaining, as he willingly gets captured by the DEO for a shot at using Supergirl to get to The Flash. Additionally, 'Star-Crossed' features a brief look at the alternate reality in which Music Meister will trap both Barry and Kara in 'Duet', which offers just enough to tease fans without revealing too much.

The entire final sequence essentially works as the introduction to 'Duet', which may not work within the overall Supergirl season but that remains to be seen when the show returns next week for another Kevin Smith-directed episode. For now, Supergirl fans will need to tune in to The Flash to learn what becomes of Kara and Music Meister.

Next: Is Supergirl’s Political Story Already Out of Date?

Supergirl continues Monday, March 27 with ‘Distant Sun’ at 8pm on The CW.