In this week's Supergirl, 'Triggers', Kara Danvers faces the metahuman Psi (guest star Yael Grobglas), who forces her to confront her oldest fear, which reveals the dark side of the Girl of Steel's origin story. The season 3 premiere of Supergirl made it clear that Kara is still very much dealing with the traumatic events of the season 2 finale, particularly her choice to put Mon-El in a pod to leave Earth, which would become uninhabitable for him as part of Kara's plan to save the world from invading Daxamite forces.

However, while Kara had dealt with the fallout from her confrontation with the Daxam queen (and Mon-El's mother) as well as Mon-El's departure by pulling away from her friends, she made a concerted effort at the end of the season premiere to make more time for the other people in her life. Still, Kara hasn't completely dealt with and gotten over her decision from the season 2 finale and its impact both on Mon-El and their relationship. More issues pertaining to Mon-El's departure - and how they relate to Kara's own history - come to light in this week's episode of Supergirl.

Related: Supergirl Faces Her Fears In ‘Triggers’ Promo

In this week's Supergirl, 'Triggers', the Girl of Steel battles the psionic abilities of the metahuman Psi, who uses her powers to force Kara to face her greatest fear. It just so happens that Kara's greatest fear stems from the scariest moment of her life - the moment her mother put her in a pod and sent her off Krypton. As viewers see in flashback - from Kara's point of view, no less - the young Girl of Steel witnessed the destruction of Krypton (and what seems to be Reign's own escape from Krypton) and remembers sitting in space alone with the knowledge that nearly everyone she knew and loved was dead.

Of course, Supergirl's origin story was covered in full during the show's pilot episode, and it even tied into the villains of the first season, since both she and Fort Rozz were trapped in the Phantom Zone for some time before finally finding their way to Earth (though not at the same time). However, while Supergirl has delved into the emotional side of Kara being the Last Daughter of Krypton - particularly in losing her mother, Alura - the series had not addressed what the experience of leaving may have been like for the young Kryptonian.

Superman, for his part, was a baby when he came to Earth from Krypton, but Kara was old enough to be aware of her planet's destruction as well as the ensuing trip - and, as we see in 'Triggers', it was a particularly traumatic experience. So much so that when Psi forces Kara to relive the experience through her psionic abilities, it triggers panic attacks in the Girl of Steel. Considering how much Kara wished to abandon her human alter-ego in favor of relying on her physically stronger Kryptonian identity in the season 3 premiere, her human panic attack about her Kryptonian past illustrates the unique blend of identities that create Supergirl.

Once again, Supergirl season 3 takes its titular heroine to a much darker place than the previous seasons have ventured, but the series continues to use Kara's darkness to highlight the lightness of her character. 'Triggers' showcases the strength of Kara as she struggles with the anxiety and fear that come with remembering her time in the pod fleeing Krypton. Further, remembering her own time in the pod brings her decision to put Mon-El in a similar pod at the end of season 2 back to the forefront, as she wrangles with the fear that he may not have survived - but even that fear is conquered by Supergirl.

Supergirl Psi Yael Grobglas

At the end of the hour, Supergirl combines the emotional strength of her human upbringing - as epitomized in her relationship with Alex - and the physical strength of her Kryptonian lineage to battle and ultimately defeat Psi. It's an altogether predictable ending to the episode, but Kara's emotional journey through reliving her experience of fleeing Krypton undoubtedly earns the Girl of Steel's heroic moment during her final confrontation with Psi. The connection to Mon-El, as well, offers an incredible depth to Kara's trauma, compounding her history of the Kryptonian pods and the fear they inspire, making it all the greater when she's able to face and overcome her fears.

Of course, there's still the thread in season 3 of Kara attempting to tamp down on any weakness and shoulder her burdens on her own, rather than turning to Alex or J'onn for help as quickly as she would have prior to the season 2 finale. As in the season 3 premiere, it affects all aspects of Kara's life, including her job at CatCo, which is now owned by Lena Luthor. With Lena taking an incredibly hands-on approach to her latest acquisition, it causes some friction in her friendship with Kara - which no doubt makes fans wonder when Lena will discover Kara's secret identity as Supergirl.

Still, with Kara continuing to put some distance between her and her friends that are also in the know about Supergirl, it may be better for Lena not to know. Plus, Kara and Lena's friendship will no doubt be made complicated enough with the appearance of Samantha Arias (aka Reign) in a pivotal role in L Corp. It remains to be seen how long Kara will continue on this darker storyline, but Supergirl season 3 is just as strong as ever.

Next: Can Supergirl Move On From Losing Mon-El in Season 3?

Supergirl season 3 continues with 'Far from the Tree' next Monday at 8pm on The CW.