Ep 8. Crisis on Earth-X, Part 1

In Supergirl season 3 episode 8, titled "Crisis on Earth-X, Part 1," Kara Danvers, also known as Supergirl, is thrilled to be attending the wedding of her friend, Barry Allen, also known as The Flash, and his fianceé, Iris West. However, the joyous occasion is disrupted by the arrival of Nazi soldiers from an alternate Earth, known as Earth-X.

The Nazis are led by Overgirl, who is an evil version of Kara from Earth-X. Along with her is her partner and leader of their army, Dark Arrow, who is a twisted version of Oliver Queen from Earth-X. The Nazis are on a mission to capture Supergirl and her friends to take them back to their Earth for unknown purposes.

Kara and Oliver team up with their respective allies from Earth-1, including The Flash, Arrow, White Canary, and others, to fight off the Nazi invasion. However, they soon realize that their adversaries are not the typical Nazis they have seen before and that their enemies from Earth-X possess advanced technology and weaponry unlike anything they have encountered.

As the battle rages on, secrets are revealed, and alliances are formed. Kara also struggles with some personal issues as she faces her doppelganger from Earth-X and learns more about her alternate self. The episode is full of action, suspense, and drama as the heroes fight to protect their world and prevent the Nazis from succeeding.

Overall, Supergirl season 3 episode 8 is an exciting start to the crossover event, "Crisis on Earth-X," that features heroes from all the CW's DC shows coming together to fight a common enemy. The episode sets the stage for the rest of the crossover and leaves viewers eager to see how the story unfolds in the subsequent episodes.