Supergirl Show Summary, Upcoming Episodes and TV Guide

Lillian comes up with the ultimate weapon to drive the Daxamites off of Earth, but Supergirl is reluctant to make the sacrifice necessary. Instead, she challenges Rhea to a ritual trial by combat to save National City and Earth. Superman returns. Cat Grant offers Supergirl some sage advice.

Alien refugees, the Phorians, trigger telekinetic quakes every time that Lena and Rhea activate the portal. While James tries to get through to one alien boy who knows where the others are, the DEO tries to find the portal before it's too late for National City.

Lena's ex Jack Spheer arrives in National City to roll out a new nanite medical procedure. However, Kara ;soon realizes that something more is going on when one of the human test subjects die under mysterious circumstances. Meanwhile, Lyra comes between Winn and James in their crimefighting efforts.

Mon-El's parents arrive to bring home and help restore Daxam to its former glory... and Supergirl realizes that Mon-El has been lying to her. Meanwhile, Winn discovers that Lyra has set him up when he's the prime suspect in a museum robbery. The Music Meister puts Supergirl into a coma and the story line concludes in The Flash: 'Duet', Season 3, Episode 17.

The DEO manages to rescue Jeremiah from Cadmus, but Mon-El's suspicions soon drive a wedge between him and the Danvers sisters. Meanwhile, Cadmus continues with its master plan to cleanse the planet of alien influence.

Metallo breaks Lillian out of jail and the evidence shows that Lena was responsible. Kara is the only one who believes that Lena is innocent, and sets out to prove it.

Livewire escapes prison, but the DEO soon realizes that she wasn't a willing escapee. Meanwhile, Megan collapses and Hank refuses to mind-meld with her to find out what is wrong with her, and James considers telling Kara that he's Guardian.

When the Danvers celebrate Thanksgiving, Alex tries to find the right time to tell her mother Eliza that she's gay. Meanwhile, Lena is forced to choose when Supergirl tells her that Lillian plans to unleash a virus that will wipe out every alien in the city.

Crossover among four CW shows: Supergirl 'Medusa'; The Flash 'Invasion!'; Arrow ‘Invasion!'; DC's Legends of Tomorrow 'Invasion!'

Supergirl battles a scientist who has been possessed by an alien parasite, giving the ability to drain the lifeforce from anyone he touches. Meanwhile, Alex comes out to Kara, and the Guardian makes his first public appearance.

While Hank tries to bond with Megan, Supergirl and Alex discover that a woman named Roulette is running an underground fight club using aliens as gladiators. Meanwhile, Mon-El convinces Winn to take him out for a night on the town.

Cadmus creates a second Metallo and declares war on any aliens on Earth. Meanwhile, Kara finds her new boss less than sympathetic, and Cat gives her surprising news.