CBS is about to premiere a new show this month titled "Code Black," a medical drama set in one of the busiest emergency rooms in Los Angeles. 

The show's lead, Dr. Leanne Rorish, will be played by Oscar winner Marcia Gay Harden. In a new interview, the actress revealed how the show will be different from other medical dramas and how the cast prepared for their scenes in the ER.

Speaking to CBS News, Harden said her character is the no-nonsense Residency Director of the ER.

"She is fierce, tough, and purposeful, with a heartache the size of Mississippi. She practices battlefield medicine, and with cowboy nonchalance and MacGyveresque ingenuity saves lives," she said, adding that Rorish teaches and that her every action is about teaching her residents to become better doctors.

The star revealed that she and the rest of the cast went through medical "boot camp" for a crash course in terminology and performing real-life procedures. 

"We had the blessing of real doctors and medical personnel helping us do things like … oh, intubate a mannequin, for example," she explained. The actress likened the experience to being at NASCAR as everyone had to rush in to save a patient, with only two to 10 minutes to stabilize a person. 

Viewers should be prepared to see a lot of blood since the series takes place in an emergency room. Harden said, "Nothing pristine or steel grey here … the ER is a mess at the end of the day!" 

As for what makes "Code Black" different from other medical dramas, the actress said that it's the style of filming, "docustyle" or documentary-style, which sets it apart from other shows. Harden said that they are drawing on the successes of other medical shows like "ER" and "Grey's Anatomy," but ultimately, it's the values that the show imparts — health, family, love, community — that stands out to her. 

Joining Harden in the cast are Luis Guzman as Jesse Salander, Raza Jaffrey as Dr. Neal Hudson, Benjamin Hollingsworth as Mario Savetti, Bonnie Somerville as Christa Lorenson, Melanie Chandra as Malaya Pineda, and Harry Ford as Angus Leighton. 

"Code Black" premieres on Wednesday, Sept. 30, at 10 p.m. on CBS.