Kristen Stewart Says That Nicole Kidman Was Originally Supposed To Be The Lead In ‘Panic Room,’ Not Jodie Foster

File this one under: Movies That Could Have Looked a Lot Different. On Monday night, Kristen Stewart dropped a seriously obscure piece of movie trivia on Stephen Colbert’s audience when she told a story about Nicole Kidman. (No, that’s not the shocking part.)

Stewart shared that she and Kidman have known each other for years because they worked together on a movie, which Kidman ultimately had to drop out of. That movie? David Fincher’s claustrophobic 2002 thriller Panic Room.

Colbert seemed as surprised as the rest of us when he asked, “She was going to be the Jodie Foster role in Panic Room?” Stewart confirmed that she was indeed—and, in fact, that “we rehearsed for weeks.” Stewart admitted that it was a long time ago, and that she was 10 years old when they began filming the movie, but turned 11 during production. She remembers that birthday vividly because “Jodie Foster got me a mariachi band for my eleventh birthday.” (We assume not to keep?)

Stewart, who is now 31, who was on the show to promote her new film Spencer, in which she portrays the late Diana, Princess of Wales and the hell she endures over the course of a single Christmas holiday with the royal family. Stewart is receiving lots of awards buzz for the role.

You can watch the full clip below: