Lex Luthor’s sister arrives in National City.

Irish actress Katie McGrath has been cast in the recurring role of Lena Luthor in Supergirl Season 2.

McGrath is best known to UK fans as Morgana in BBC One’s fantasy drama Merlin, which ended in 2012. Since then, she has also appeared in Dracula and Jurassic World.

As the character name suggests, Lena Luthor is the sister of Superman’s arch-nemesis Lex Luthor. However, in Supergirl, Lena is set to strike up a possible friendship with Kara, aka Supergirl (Melissa Benoist).

TV Line describes Lena as “Beautiful, powerful, and enigmatic, Lena arrives in National City on the heels of brother Lex’s incarceration hoping for a fresh start. Lena has taken over as CEO of her family’s billion-dollar-tech company, Luthor Corp, which has been tarnished by Lex’s evil infamy. Her goal? To re-brand the empire as a force for good. Lena wants to be seen as her own person, separate from her brother. Kara is drawn into Lena’s sphere and must determine if she is friend or foe.”

Reprising their roles in Season 2 will be, Chyler Leigh, Jeremy Jordan, Mehcad Brooks, Calista Flockhart (no longer a regular due to production move),  Jenna Dewan Tatum, David Harewood, Peter Facinelli, Dean Cain and Helen Slater.

McGrath joins previously announced cast additions, Lynda Carter as the President of the United States, Floriana Lima as Maggie Sawyer, Tyler Hoechlin as Superman and Ian Gomez as Kara’s new CatCo boss.

Supergirl Season 2 will premiere on The CW on October 10th. Sky 1 airs the series in the UK.