Ep 17. Manhunter

In Supergirl season 1 episode 17, titled "Manhunter," Kara Danvers/Superwoman teams up with J'onn J'onzz/Manhunter to stop a dangerous alien threat. The episode opens with a flashback to the past when J'onn was first introduced to the Danvers family as Hank Henshaw, the head of the DEO. We learn more about his backstory and how he came to Earth as a refugee from Mars, escaping the genocide of his entire race by the White Martians.

In the present day, Kara and J'onn are faced with a new threat: a White Martian who has come to Earth seeking revenge on J'onn. J'onn is forced to reveal his true identity to Supergirl to explain the danger they are facing. They quickly realize that the White Martian, who has taken the form of a human girl named Megan, has infiltrated the DEO and is targeting J'onn's staff one by one.

As Kara and J'onn work together to stop the White Martian, they must also confront their own personal struggles. Kara feels guilty for hurting her friend James' feelings and grappling with her own alien identity. Meanwhile, J'onn must confront the guilt and trauma of being the last surviving Green Martian and the sacrifice he made to save Alex's father, which led to him being hunted by the DEO.

Manhunter is a thrilling and emotional episode that tackles themes of identity, trauma, and sacrifice. It also introduces some exciting new characters, including Megan/Martian Manhunter and the ruthless villainess Indigo. With suspenseful action sequences, heartfelt moments, and unexpected twists, this episode is a standout of the season.