Credit: CBS

Marcia Gay Harden has been re-cast as the lead in the CBS drama pilot Code Black, a role previously held by Maggie Grace.

EW has confirmed the switch and that Bonnie Somerville has been cast in as Christa, Harden’s former role.

Code Black is a medical drama set in the busiest and most notorious ER in the nation where the extraordinary staff struggle in the face of a broken system to protect their ideals and the patients who need them the most.

Harden will now play Leanne, the residency director in the ER, who is a force of nature and a force to be reckoned with.

Christa (Somerville) is a former soccer mom whose son died of cancer, Christa is now a newly minted, talented and dedicated doctor whose experience handling her son’s disease, coupled with her intuition and life experience, makes her see things that often escape her younger fellow residents.

Other cast members include Melanie Kannokada, Luis Guzman, Raza Jaffrey, and Ben Hollingsworth.