This Is Us wraps up its first season tomorrow, and we’ve already got heart palpitations thinking about what’s going to happen. The show’s star, Mandy Moore, has already told us to expect pain and grief. She wouldn’t elaborate on what exactly that means, but there’s one particularly painful fan theory that she shut down pretty hard.

Potential spoilers ahead! Last week’s episode ended with Jack (Milo Ventimiglia) getting into a car, drunk, on his way to make up with Rebecca (Mandy Moore). In the present, Kate (Chrissy Metz) tells Toby (Chris Sullivan) that she was responsible for her father’s death as a teenager, which left many viewers thinking it was Kate urging Jack to go see Rebecca that led to his death.

But there’s one fan theory that would make that scenario even more heartbreaking: that Rebecca was working with Miguel (Jon Huertas) to kill Jack so they could be together. Could it be?

“Oh my god,” Mandy told E! News. “No way. People are bananas. That is crazy.”

We might not get to learn how Jack dies in tomorrow’s finale, but since the show has already been renewed for seasons two and three, fingers crossed we’ll find out soon. As Mandy told E! News, it’s such a “monumental event for the family” that the showrunners might want to make us wait. But as for tomorrow’s show, “I think the show is ultimately hopeful, and I feel like it leaves on that note as well, in the finale.”

Are you bracing yourself for tomorrow’s finale? Tweet us @BritandCo!

(Photos via Alberto E. Rodriguez/Getty Images for Entertainment Weekly, Loreen Sarkis/Getty Images, and Marcus Ingram/Getty Images for NAACP Image Awards. h/t to E! News)