A sneak peek of ‘Mercy Street’ premieres this weekend on PBS

This weekend, PBS will premiere “Mercy Street,” a new “period show” that just might take the reins from “Downton Abbey” — which is now in its sixth and final season.

“Mercy Street” is set in an Alexandria, Virginia, at a Union Army Hospital during the Civil War, beginning in 1862. It isn’t just a show set in the Civil War. It’s a hospital drama — where the patients are soldiers, and the doctors are inventing modern medicine.

The show was created by David Zabel and Lisa Q. Wolfinger, and was produced by Ridley Scott. The ensemble cast of 18 characters includes Josh Radnor (from “How I Met Your Mother”) as Dr. Jedediah Foster; Mary Elizabeth Winstead as Nurse Phinney, a New England abolitionist; and Hannah James as Emma Green, a Confederate volunteer nurse.

The show’s co-creator, head writer, and showrunner Zabel, studied theater and fiction at Princeton University. Then, he honed his TV writing and producing chops at “ER,” NBC’s groundbreaking hospital drama. Zabel says he tries to make TV that’s intense, yet medically accurate.

“I think my capacity to do that, at times, is certainly informed by the education I had at Princeton,” Zabel said. “I have the ability to say, OK, I don’t know anything about medical science, but now I have to write a show called ER, which is wall-to-wall medical science.”

“I needed to learn quickly. I needed to be smart about it. I needed to study, and to incorporate what I needed to incorporate.”

Zabel says he brought this attitude to his current project, “Mercy Street.”

“I hadn’t studied the Civil War any more than the average student has studied it,” Zabel said. “And once we dug into this project, I really tried to become as much of an expert as I could. I felt like I needed to.”

Zabel says that having a solid foundation in Civil War medicine and history has made it a bit easier to write scenes full of emotional drama. Yet, he says, he sometimes finds it challenging to put away his research and instead focus on his creative process with his team of writers.

“There’s a point at which I stop researching. I have to stop. I can’t keep taking in intellectual information in the writing process,” Zabel said. “I study hard, I prepare hard, and then, when it’s time to write, and to draw the characters, and bring the dramatic conflict to a height, I have to turn off that part of my brain.”

“Mercy Street” is full of history, of facts and data and details. But it’s not an “educational” show. No — it has an emotional, dramatic rhythm.

In the first episode, one scene begins in the dead of night, but builds momentum forcefully. A soldier in the hospital screams for his life. A wound in his arm rips open, hemorrhaging blood. Nurse Phinney (played by Mary Elizabeth Winstead) calls out for help. But the hospital’s head surgeon, Dr. Jedediah Foster (played by Josh Radnor) is nowhere in sight.

Nurse Phinney begins to panic. Suddenly, Samuel Diggs, an African-American hospital aide (played by McKinley Belcher III), steps up and takes charge. With Nurse Phinney by his side, he examines the soldier — and finally, he ties a ligature to stop the bleeding and to save the soldier’s life.

Dr. Robert Hicks, director of the Mutter Museum at the College of Physicians in Philadelphia, confirms that the series accurately depicts how doctors performed surgery in the Civil War. 

“The doctor would know that not only does he have to get that bullet out, but when the bullet goes in, it goes through the soldier’s coat,” Hicks explained. “The surgeon is going to be very concerned to get the bullet out and any detritus that the bullet captures on the way in. If there’s anything left behind, the surgeon knows there is a good chance of infection.”

Hicks served as an expert for the second season of the show — but PBS has yet to confirm whether it will pick up “Mercy Street” again next year.

He says that Civil War military hospitals founded emergency medicine as we know it today.