Lost’s Maggie Grace has been hired to be the top doctor in the CBS Pilot Code Black The Hollywood Reporter has learned.

Grace will be joining the cast as Leanne, the ER resident doc who is described as a force to be reckoned with. Cast mates Marcia Gay Harden (How to Get Away With Murder) plays a soccer mom-turned Dr. and Melanie Kannakoda as a new ambitious resident in the hospital.

Based upon a documentary, the medical drama pilot is set in the busiest emergency room in the country. The extraordinary staff confronts a broken system in order to protect their ideals and the patients.

The script will be written by Michael Seitzman of Intelligence and he will also executive produce the ABC Studios and CBS Television Studios co-production. Marti Noxon, Linda Goldstein Knowlton, McGarry and David Semel will join Seitzman to executive  produce, with Semel also directing the pilot.