You and Tad Hamilton costar Topher Grace both grew up in Darien, Conn. So did you meet Topher back in Darien or in L.A.?
When I moved out to Hollywood when I was 18, we saw each other at a party. He came up to me and said, "Are you Kate? Did you once live in Darien?" It's such a small town. ... I was cast first in this movie and then the word came down that they wanted to cast Topher Grace as my hometown buddy, Pete. It was fated, almost. It's one of those weird coincidences that makes you think, like, there's some kind of master plan.

Now you're shooting the Bobby Darin biopic Beyond the Sea with Kevin Spacey. How is it playing teen idol Sandra Dee, the original surfer-girl movie star?
It's so neat. I get to wear a full-on platinum blonde wig and black eyeliner and have bright red lips. I have the most amazing costumes. Sometimes, I look in the mirror, and I don't even recognize myself.

Is the movie a love story?
It kind of is. Bobby Darin married Sandra Dee when she was 16.

Do you sing in the film?
No, but Kevin does, and he's eerily identical to Bobby's voice. It's going to shock everyone.

Is there any truth to the story that you gave director/actor Robert Redford a Christmas card picture of yourself rather than a headshot, and you still got your first part in 1998's The Horse Whisperer?
Yeah, that's totally true. It was a little 4-by-6 photo. When they said to bring in a picture of myself, I didn't understand that you were supposed to have headshots. So I just brought our family Christmas card. It was my first audition.

Was that a fun movie to do, being an avid rider?
I was 13 and just a kid who was into horses – I wasn't into boys yet. My mother was shaking with excitement about Robert Redford. It was such a flukey way to fall into it. Fate can be very strange sometimes.

Did it feel like fate that you'd be an actress?
I thought it would just be a really fun experience. I thought, This will be great. I'll ride horses all day and get out of school and maybe have a great experience. Through my love of horses, I wound up falling in love with acting – accidentally. It was cool. It all worked out.