The footage starts out on a high note, showing photos from their engagement announcement and wedding, but the pair explain things quickly turned south for them, with flashes of tabloids and negative headlines flooding the screen.
"There's a hierarchy of the family," states the dad-of-two, 38. "You know, there's leaking, but there's also planting of stories."
The former actress' lawyer Jenny Afia notes of the scrutiny, "There was a war against Meghan to suit other people's agendas."
A voiceover claims the negativity stems from "hatred and race," while Harry acknowledges, "It's a dirty game."
"The pain and suffering of women marrying into this institution this feeding frenzy ... I was terrified," adds the Invictus Games founder as video clips of his late mother, Princess Diana, are displayed. "I did not want history to repeat itself."
"No one knows the full truth," Harry concludes in the trailer. "We know the full truth."
The second part of the streaming service special will air one week later on Thursday, December 15.
Prior to the trailer dropping, the couple stayed relatively mum on the Liz Garbus-directed documentary, though the Suits alum, 41, hinted to Variety she wasn't completely satisfied with the final result.
"It’s nice to be able to trust someone with our story — a seasoned director whose work I’ve long admired — even if it means it may not be the way we would have told it. But that’s not why we’re telling it," shared the mom-of-two. "We’re trusting our story to someone else, and that means it will go through their lens."
As OK! reported, royal experts such as biographer Tom Bower believe the duo will be "ostracized" from the monarchy if the documentary shades them in any way.
For more on the royal family, tune into the critically acclaimed podcast, "The Firm: Blood Lies and Royal Succession." Listen below.