To get ready for the Supergirl season 3 premiere, which is only days away, we look back at season 2.

Supergirl‘s second season was marked by some pretty big changes, particularly a change of network as the show moved from CBS to The CW. The network moved also included a production change, as filming moved from California to Vancouver, which led to some cast shakeup. However, it also allowed for more crossover with the the other Arrow-verse shows.

Before the Girl of Steel returns for her third season, let’s review the major events of season 2.

Introducing the Man of Steel

Supergirl‘s first season featured Kara’s famous cousin in indirect ways, but with Kara now a hero in her own right, season 2 brought Superman in and allowed the two Kryptonians to work together. Teen Wolf‘s Tyler Hoechlin imbued Clark Kent with a levity and humility that lit up the screen. Yet he never outshone Kara.

Clark appeared in the first two episodes of the season before returning to Metropolis. He then returned in the finale; brainwashed by the Big Bad, he fought Kara and lost in a close contest. Kara’s victory marked her as Earth’s champion, setting the stage for her to fight Rhea for the fate of the planet.

Cat Grant goes on sabbatical

When Supergirl moved its production to Vancouver, Calista Flockhart was not willing to make the move to Canada. Thus her status on the show was scaled back from series regular; to explain her absence, Cat Grant took a leave of absence from CatCo and left James in charge.

She returned for the Daxamite invasion in the final episodes of the season, first alongside the president and then stepping back into her role as the head of CatCo. She once more served as a mentor to both Kara and Supergirl — and quietly revealed to the audience that she knows Kara is Supergirl.

Mon-El, prince of Daxam, arrives

Supergirl‘s first season cliffhanger was about a Kryptonian-looking pod landing in National City. The inhabitant of that pod was Mon-El, the Daxamite prince (though he hid this fact from Kara for most of the season). Daxamites and Kryptonians were bitter enemies, and the destruction of Krypton led to the end of Daxam as well. At first, Kara and Mon-El butted heads, but the two eventually started dating.

However, the arrival of Mon-El’s parents, the king and queen of Daxam, changed everything. Mon-El, having slowly evolved from selfish to heroic, refused to help his parents reunite Daxamites who were scattered around the universe. Rhea, queen of Daxam, eventually led an invasion of Earth with the intention of establishing New Daxam.

The solution to defeating Rhea and the Daxamites was to release lead into the atmosphere, as it is deadly to Daxamites. While Rhea was defeated, this forced Mon-El to leave the planet to save his life. Moments after entering space, he was sucked into a mysterious wormhole.

A Luthor and a Super working together

The other major character introduction in Supergirl season 3 was Lena Luthor, the adopted younger sister of Lex Luthor. It turns out, however, that Lena is half-Luthor, as she is the daughter of Lionel Luthor and a mistress. Lena came to National City to take over Luthor Corp, renaming it L Corp, and get out from her infamous brother’s shadow.

Though her last name made Clark skeptical of her at first, Kara believed in Lena and the two soon became close. Supergirl also stood in support of her. Lena’s loyalties have remained in tension, however, as her adoptive mother — Lillian — is the head of Cadmus. She continually proved herself on the right side through season 3, and Kara remained a steady supporter.

Alex comes out, finds love

Perhaps the most moving arc of Supergirl season 2, Alex was given the opportunity to start thinking about herself rather than focusing entirely on protecting Kara. After meeting Detective Maggie Sawyer and spending time with her, Alex realized that she is, in fact, a lesbian. With Kara’s support buoying her, Alex took a leap and started seeing Maggie.

Working together both personally and professionally, Alex and Maggie soon fell in love. And in the season finale, Alex proposed to Maggie.

James becomes Guardian

James underwent some major changes in season 2. Not only did Kara break off their potential romance before it could really begin, but he was also left in charge of CatCo in Cat Grant’s absence. But with Winn moving to the DEO and Kara spending more time there than at CatCo, he felt left out and unable to help the way he had been when the trio had worked together in season 1.

James took inspiration from Kara and Clark and decided to become a vigilante; with Winn helping him from a van, Guardian worked to help people on the street-level. Though Kara was angry when she first learned the truth, she eventually came around and the friendship was mended.

Meet M’gann, aka Miss Martian

J’onn was shocked to learn that he is not the only Martian on Earth. He met M’gann M’orzz, who claimed to be the last daughter of Mars. However, she turned out to be a White Martian who felt guilty for her actions and the actions of her people against the Green Martians. She fled from Mars to Earth and went into hiding.

Though J’onn felt betrayed by M’gann pretending to be a Green Martian, the two eventually fell in love. However, M’gann felt compelled to return to Mars and recruit other peaceful White Martians.

Jeremiah lives — but he’s a Cadmus agent

One mystery that was introduced in Supergirl‘s first season was the survival of Jeremiah Danvers. It turns out he didn’t die helping to save J’onn from Hank Henshaw; he was recovered by Cadmus. Whatever happened over the years of his captivity among the anti-alien group led by Lillian Luthor, he now seems to be a loyal agent.

Lions and tigers and crossovers, oh my!

Despite living on Earth-38, Kara managed to make her way to Earth-1 more than once. First, Barry recruited her during the Invasion! storyline in which an alien race known as the Dominators paid Earth-1 a visit. J’onn and Mon-El then brought her to Earth-1 when she was knocked into a musical-themed coma, alongside Barry, by Music Meister.

Watch the official trailer for Supergirl season 3 below:

Supergirl season 3 premieres Monday, October 9 at 8:00 p.m. ET on The CW.