On the Supergirl 100th episode, Kara is visited by Mr. Mxyzptlk, who offers her the chance to turn back time and “fix her friendship with Lena, telling her the truth before Lex has a chance.

Probably the most anticipated episode of Supergirl season 5, the Supergirl 100th episode, isn’t my favorite episode of the season, or my favorite milestone episode by any means, but it does offer a lot of time for reflection on the past and certain relationships between the characters, which I absolutely loved.

We, obviously, had the chance to view the Supergirl 100th episode early, and have put together a few teases of what’s to come along with our spoiler-free review. Unlike usual, we’ll start with our spoiler-free review, so only scroll down further if you want to risk seeing a few minor things about the episode!

‘Supergirl’ 100th episode spoiler-free review

Of the 13 episodes of Supergirl season 5, the Supergirl 100th episode ranks third on my list of favorites, behind Supergirl season 5, episode 1 and episode 8.

Focusing primarily on Kara, we see the mission of the season — the fight for Lena’s soul — come to the forefront as Kara has an opportunity to right her wrong, going back in time to fix her mistake and tell Lena the truth, preventing her from the hurt she felt over this betrayal.

Melissa Benoist and Katie McGrath give an incredible performance, capturing who their characters were in the past and are now with such ease and effortlessness, it’s like all of these “flashbacks” were shot years ago… though, purely from Benoist’s Arrow-verse material wig, we know that is not the case.

Of milestone episodes like this, I’ve definitely seen many that are better. Supergirl ’s is better than Arrow and The Flash ’s were, in my opinion, but I have to admit that I’m upset that the writers did not take the opportunity to reflect on both of the main relationships that have influenced Kara over the years: her best friend, Lena, and her sister, Alex. (More on this in a tease below.)

While the Supergirl 100th episode is a great episode, it also feels like more could have been done to honor the series and where it started, where it has gone, and where it will go from here. With so many changes behind-the-scenes since season 1, maybe that was difficult to do. Regardless, what I appreciate most about this episode is how it cements how much good Kara has done and will do for the world and her friends, which is also quite important.

I’m excited to watch this episode for the second time and see if that helps me appreciate it even more, knowing what’s coming and what it does to set up the future of the season and the show. But I don’t need to watch again to understand how important this episode is. It’s one that you truly can’t miss, despite what emotions it may bring up, because it’s so important for Kara and Lena’s futures.

‘Supergirl’ 100th episode screener secrets

Alex, Kara, and J’onn

Though not the primary focus of the Supergirl 100th episode, the relationship between Kara, Alex, and J’onn, as the two people who have been there since she first became Supergirl, is acknowledged. It’s perhaps not enough for this core relationship, especially that of the Danvers sisters, but it at least provides an inkling of how important those two have been on Kara’s journey.

There’s quite a sad (but ridiculously short) scene of Alex, which has something to do with the gravestone in the trailer (seen below). Honestly, I really wish the Danvers sisters relationship had gotten the level of focus it deserved.

Reveals, alternate realities, guest appearances

Obviously, the Supergirl 100th episode has Kara seeing what life would have been like had she told Lena her secret at various points during their friendship. All in all, there’s about four different alternate realities that she visits, each far different than the last (and about one per season of the show). Three have to do with previous moments in Kara and Lena’s friendship, while one is much darker and different than the others.

(Unrelated, but in one of these realities, we see Nia with such control over her powers and Kelly as Guardian, so it’s clear that the writers know what they have the potential to write, what we want to see, and they just aren’t doing it. Nia has, like, a minute of time on-screen, while Kelly has her obligatory one line per episode. A major disappointment.)

Of all of the guest appearances, don’t really get your hopes up for more. Basically, every big return has already been revealed with press releases or pictures taken on set (by paparazzi), which is quite sad, but we see a couple of these characters far more than I had anticipated.

That said, there are a couple of others from Supergirl season 3 that make an appearance, too.

An ending just as expected as it was unexpected

From the ending of the Supergirl 100th episode, it seems the writers are setting up, at the very least, part of their story for the rest of the season. The ending defines something that’s been wavering all season, while putting Kara in a better position than she’s been in for a while. She seems stronger, more together, and ready to continue on with her super life, despite whatever the future holds.

We all know Kara learns a lesson at the end of this magical adventure with Mxyzptlk, and it’s definitely different than what I thought it would be. The ending solidifies how much Kara has grown over her years as Supergirl, while still showing that she’s not perfect. She’s doing the best she can, which is all anyone should ask of her.

Here’s to many more episodes of Supergirl, following the Supergirl 100th episode on Sunday, February 23 at 9 p.m. ET on The CW!