A first look at Meghan Markle and Prince Harry’s upcoming interview with Oprah Winfrey was released on Sunday—and according to Oprah, no subject was “off-limits” during the sit-down. “You’ve said some pretty shocking things here,” the media mogul told the Duke and Duchess of Sussex in one teaser clip.

In a promo for the primetime special, Harry, who along with Meghan stepped back as senior members of the royal family last year, revealed that his “biggest concern was history repeating itself.” Discussing his late mother Princess Diana, the Duke admitted to Oprah, “I’m just really relieved and happy to be sitting here, talking to you with my wife by my side. Because, I can’t begin to imagine what it must have been like for her going through this process by herself all those years ago because it has been unbelievably tough for the two of us, but at least we have each other.”

During the interview, Oprah asked Meghan if she was silent or silenced. She also told the Duchess, “Almost unsurvivable sounds like there was a breaking point.”

Gayle King recently revealed on CBS This Morning that Oprah’s interview with the Sussexes is “the best” she’s ever done. “It’s their first major broadcast since giving up their senior royal duties … and I’ve heard from reliable sources – this is Oprah talking – that it’s the best interview she’s ever done,” Gayle said (via People magazine).

Oprah with Meghan and Harry: A CBS Primetime Special airs on Sunday, March 7. It was announced on Feb. 15 that Oprah, who was a guest at the Duke and Duchess’ 2018 royal wedding, was going to sit down with the California-based couple for an “intimate conversation.”

“Winfrey will speak with Meghan, The Duchess of Sussex, in a wide-ranging interview, covering everything from stepping into life as a Royal, marriage, motherhood, philanthropic work to how she is handling life under intense public pressure,” a press release for the special said. “Later, the two are joined by Prince Harry as they speak about their move to the United States and their future hopes and dreams for their expanding family.”