The Best Episodes of 'Supergirl'

Season 5, Episode 13

Mxyzptlk returns with a proposition for Kara – what if she could go back in time and tell Lena her secret before Lex did, would things turn out different? Looking back over key moments throughout the series, Kara must decide if she wants to change history to become friends with Lena again.

Season 2, Episode 1

In the season two premiere, Kara teams up with her cousin, Superman (TYLER HOECHLIN) to stop a new threat. And Hank is stunned by the pod that crashed last season.

Season 5, Episode 9

The Monitor sends Harbinger to gather the worlds’ greatest heroes - Supergirl, The Flash, Green Arrow, Batwoman, White Canary, The Atom and Superman - in preparation for the impending Crisis. With their worlds in imminent danger, the superheroes suit up for battle while J’onn and Alex recruit Lena to help them find a way to save the people of Earth-38.

Season 3, Episode 3

Eliza throws Alex and Maggie a wedding shower, which causes Maggie to reach out to her estranged father. Supergirl joins J’onn on a personal mission.

Season 1, Episode 18

Supergirl gains a new ally when The Flash (GRANT GUSTIN) crosses over from an alternate universe to help her battle Livewire and Silver Banshee.

Season 1, Episode 13

Kara’s friends must find a way to save her life when a parasitic alien attaches itself to her and traps her in a dream world where her family is alive and her home planet was never destroyed. Also, Alex, Hank and the DEO must fend off a Kryptonian attack while Kara is out of commission.

Season 3, Episode 5

When Morgan Edge (ADRIAN PASDAR) blames Lena (KATIE McGRATH) for the fallout from the Daxamite bomb, Kara teams up with Samantha (ODETTE ANNABLE) to clear Lena’s name.

Season 1, Episode 7

Kara must rely on their inner strength and courage when an earthquake strikes and she's lost her powers. Also, Alex's mistrust of Hank reaches a breaking point.

Season 5, Episode 7

Supergirl finally learns the truth about Lena while tangling with Leviathan. J'onn J'onn makes a discovery about his brother's whereabouts.

Season 1, Episode 16

Kara turns on her friends and the citizens of national City after being exposed to Red Kryptonite makes her malicious and dangerous.

Season 3, Episode 1

Kara deals with the loss of Mon-El by focusing all her energy on being Supergirl and the mysterious new threat against National City. Alex confesses a secret to Maggie about their impending nuptials. A citizen of National City has a mysterious connection to Kara, and Lena makes a bold move.

Season 1, Episode 1

After 12 years of keeping her powers a secret on Earth, Kara Zor-El, Superman's cousin, decides to finally embrace her superhuman abilities and be the hero she was always meant to be.

Season 5, Episode 14

Lex proceeds to lay an intricate plan to bring Lena closer to him, defeat Leviathan’s latest attack, and pit Supergirl and team against Leviathan. It is also revealed how Lex came into power after Crisis.

Season 3, Episode 2

Psi, a thief with psychic powers, attacks National City. Able to immobilize people by tapping into their worst fears, Psi proves a formidable opponent for Supergirl. Meanwhile, James and Lena are at an impasse, and Samantha starts her new job at L-Corp.

Season 1, Episode 10

Kara does her best to support Winn when his father, the Supervillain Toyman (HENRY CZERNY), breaks out of prison and seeks out his son for unknown reasons.

Season 1, Episode 4

Kara's Thanksgiving may be ruined when her foster mother comes for a tense visit and a volatile CatCo employee (BRIT MORGAN) is transformed into the villainous Livewire.

Season 5, Episode 11

As Supergirl tries to thwart a Toyman copycat, Winn Schott returns from the future.

Season 1, Episode 5

Kara is pulled in opposite directions when she babysits Cat's son, Carter (LEVI MILLER), while trying to stop a series of bombings. And Lucy Lane (JENNA DEWANT TATUM) appears.

Season 1, Episode 17

J'onn J'onzz reveals the details of meeting Kara and Alex's father, Dr. Jeremiah Danvers (DEAN CAIN), and assuming Hank Henshaw's identity.

Season 1, Episode 2

When Kara’s attempts to help National City don't go according to plan, she must put aside the doubts that she -- and the city's media -- has about her abilities in order to capture an escapee from the Kryptonian prison, Fort Rozz. Also, Cat pressures James to use his connection to Superman to get her an interview with Supergirl.

Season 1, Episode 20

Supergirl must battle with an unexpected foe and risk everything - including her life - to prevent Non and Indigo from destroying every person on the planet in the season finale.

Season 3, Episode 4

Kara investigates a secretive new group whose leader, Thomas Coville (CHAD LOWE) has a mysterious connection to Supergirl. Meanwhile, J’onn confesses an old secret.

Season 1, Episode 6

Anger gets the better of Kara when she goes too far during a training exercise with Red Tornado (IDDO GOLDBERG), a military cyborg commissioned by Lucy Lane's father.

Season 1, Episode 8

Kara goes head-to-head with her aunt Astra (LAURA BENANTI) when she challenges Kara's beliefs about her mother. Also Cat's CEO position is threatened by a hacker at CatCo.