Ep 1. Girl of Steel

Supergirl season 3 episode 1, titled "Girl of Steel," starts off with Kara Danvers dealing with the aftermath of the season 2 finale, where she had to say goodbye to Mon-El and send him away from Earth. Her mourning is interrupted when she discovers a mysterious Kryptonian pod has crashed on Earth, and a young girl emerges from it.

The girl, later revealed to be Samantha Arias, has no memory of her past, but has impressive physical abilities. Kara becomes determined to help Samantha find out where she came from and what her powers mean. However, as she digs deeper into Samantha's past, Kara realizes that Samantha's arrival may not have been a coincidence, and she may be in danger.

Meanwhile, Kara is dealing with changes in her personal life. Her sister, Alex, is trying to start a family with her girlfriend Maggie Sawyer, but the process is not going as smoothly as they had hoped. Kara's best friend Winn is also going through some changes as he starts a new job at the DEO, working with a new boss who challenges him in ways he didn't expect.

As Kara navigates these personal and professional challenges, she also has to deal with a new threat in the form of a group of mercenaries hired by a mysterious figure known only as "The Boss." The group, led by a woman named Bloodsport, is targeting powerful individuals in National City, including Lena Luthor, who has taken over L-Corp in the absence of her brother Lex.

As Kara tries to protect her loved ones and the people of National City, she also has to confront her own feelings of grief and loss, and figure out how to move forward without Mon-El. With new enemies on the horizon and old wounds still fresh, Kara's journey as Supergirl is just beginning in season 3.

Overall, Supergirl season 3 episode 1 lays the groundwork for a season filled with emotional and physical challenges for Kara and her friends. The introduction of Samantha Arias adds a new dimension to the show, as Kara tries to help her unravel the mystery of her past while also protecting her from those who seek to control her. As always, the show combines action and heart in equal measure, leaving viewers eager to see what happens next.