John Goodman, Michaela Coel on the "Painful" Research Process for 'Black Earth Rising'

The stars open up to The Hollywood Reporter about revisiting the 1994 Rwandan genocide to prep for Netflix's new international crime drama.

When Michaela Coel and John Goodman signed on to star in Black Earth Rising, the BBC 2 hit that is now streaming for American audiences on Netflix, they admittedly knew very little about its heavy subject matter.

Black Earth Rising — written and directed by Hugo Blick — centers around Coel's character, Kate Ashby, who survived the 1994 Rwandan genocide as a child and grows up to become a legal investigator in the law office of Michael Ellis (Goodman). When Kate's adoptive mother takes on a case prosecuting a militia leader who was involved in Rwanda's civil war between the country's Hutus and Tutsis, Kate and Michael power through a series of struggles by delving deep into the African nation's unpleasant past.

To prep for their roles, Coel and Goodman told The Hollywood Reporter in a recent In Studio interview that they had to educate themselves in real life as well.

"[It was] painful. Not exactly guilt-producing but, yeah, guilt-producing," Goodman said of the research process. "Just how ignorant I'd been … Unfortunately, it landed on the people of Rwanda with both feet. It always had. They were always the ones to suffer."

According to Coel, she immediately turned to Stephen Kinzer's book A Thousand Hills in which the author details how Rwanda healed following the genocide that left an estimated 500,000 to 1 million people dead in a span of 100 days.

"I too didn't know anything until I got my first script, and I was embarrassed by my lack of knowledge," said Coel. "How did I not know this? I was asking everybody instead of just accepting my own ignorance."

Added the U.K. native, "The scripts led me down a path of trying to inform myself of things that are quite painful."

Blick — who also stars in Black Earth Rising — joined Goodman and Coel for their chat with THR and explained why he thought the pair's respective comedic backgrounds benefited their performances in his drama. Goodman is best known for playing Dan Conner on Roseanne and its spinoff, The Conners, while Coel rose to fame though her British sitcom, Chewing Gum, which premiered in 2015.

"I think it's the highest form of rhythmic understanding," Blick enthused of his versatile stars' comedy work. "I think if you can deliver a great comedic line as both of these two can, I think drama is just a little easier."

For more on Black Earth Rising — including its political parallels and transition to Netflix — watch the video above.