Something borrowed. Something blue. Something very, very bad. 

That’s the uneasy promise behind the trailer for Something Very Bad Is Going to Happen, the upcoming horror series starring Adam DiMarco and Camila Morrone. The story follows bride-to-be Rachel (Morrone) as a dreamy proposal spirals into a slow-burn nightmare, leaving her to suspect that walking down the aisle to marry Nicky (DiMarco) may end in something far more sinister than a wedding vow.

The trailer opens like a love story: Rachel and Nicky agree to marry, vow to skip the “wedding bullshit,” and settle into a cozy home in the woods. For a moment, everything feels like the start of a happily ever after. But the mood quickly shifts, and the idyllic setting starts to feel less comforting. “Ever since we got here, I feel like something weird is going on,” Rachel says uneasily.

In the new matrimony-twisted horror series created by Haley Z. Boston — and executive produced by the Duffer Brothers — the days leading up to Rachel and Nicky’s wedding become increasingly unsettling. “They start to experience this feeling of dread that something very bad is going to happen, though they don't know what it is,” Boston tells Tudum. “It’s really about having doubt in the week leading up to this huge commitment.”

Nicky dreams of a simple wedding ceremony, while Rachel can’t shake the sense that fate has other plans. “We are still getting married, right?” Nicky asks in the trailer. The question then hangs in the air, like the start of something going very wrong.

At the center of the story is Rachel and Nicky’s complicated dynamic, and the creeping doubt that threatens to unravel it. “Rachel and Nicky have a really solid relationship … but there are fundamental differences and some misunderstandings,” Boston explains. Nicky is “very loving, caring, romantic,” someone who grew up surrounded by unconditional love, she notes, while Rachel comes from a far less stable past and sees in him something that has long been missing from her life. “They complement each other in that where he’s missing an edge, she has it,” the showrunner says. But as the wedding week unfolds, those differences begin to surface — revealing the cracks in what first looked like the perfect match.

The trailer also introduces viewers to Nicky’s tight-knit, slightly intimidating family, whose traditions Rachel may soon be stepping into. “The Cunningham family is sort of … I won't say that they’re a perfect family, but they have a lot of love, care, and tradition,” Boston explains, noting that sense of togetherness is something Rachel “did not grow up with.”

The clan includes matriarch Victoria (Jennifer Jason Leigh), a fiercely controlling romantic who’s turned marriage into the family’s ruling religion, and her husband Boris (Ted Levine), a loyal idealist whose life revolves around upholding the love story she insists on telling. Among the Cunningham siblings, Jules (Jeff Wilbusch) is the “black sheep,” Portia (Gus Birney) is a chaotic wild card who “says whatever she’s thinking,” and Nicky is the family’s peacekeeper and favorite child. 

Also circling the wedding-week drama are Jules’s wife and son, Nell (Karla Crome) and Jude (Sawyer Fraser), as well as a mysterious figure played by Zlatko Burić. All of them complicate Rachel’s uneasy introduction to the family she may soon join.

But those knotty family dynamics are only part of the show’s slow-building unease. As Boston puts it, the tone is “unsettling, getting-under-your-skin dread,” mixed with character-driven storytelling, trading jump scares for psychological unraveling. She points to genre classics like Carrie and Rosemary’s Baby as key inspirations, explaining that the series lives somewhere between those worlds, blending paranoia, dark humor, and emotional drama. “I love horror. It’s natural to me,” she says. “It’s the way that I process my own emotions and feelings and my own understanding of the world. Horror allows you to explore taboo feelings and take all of these fears and give them some bite.”

All that creeping dread ultimately leads back to the question at the heart of the story: what if you’re about to commit to the wrong life? “The week leading up to a wedding is such a ripe comparison to walking the plank,” she says of the show’s central metaphor. “You’re marching toward your death if it’s the wrong choice.”

For Rachel, she seems certain — at least in the trailer. “If there is such a thing as a soulmate, then yes, Nicky is my soulmate.” Famous last words?

Something Very Bad Is Going to Happen premieres March 26, when all eight episodes arrive on Netflix.