As if it wasn’t exciting enough that part of a movie called “Thoroughbreds” was being shot in Wellesley Square this week, we’ve learned that a Wellesley family’s horse will be appearing in the film.

It’s still something of a mystery how the 15-year-old horse, called Sausages/Odin (stage name: Odin), got picked to appear in the film, says owner Bec Lowe, who is graduating from Wellesley High School on Friday.

“He’s never been in a movie before. Apparently they were just out and about looking for barns in the area and they found my barn [Harlequin Stables in Westwood] , saw my horse and thought he was perfect,” Lowe says. “It really only started being a conversation after I got back from April vacation. My barn owner asked ‘How’d you like it if Odin was in a movie’ and I said that’d be cool and then it’s just been the photo shoot in May and filming.”

Lowe says she isn’t exactly sure what role Sausages/Odin will play in the movie, which we’ve seen described as a thriller/dark comedy/drama about two teenage girls in suburban Connecticut who rekindle their unlikely friendship after years of growing apart — and there’s a murder in there somewhere (we suspect the horse did it!). The horse was filmed at his barn for one scene and was also in a photo shoot that Lowe attended. “It’s very hush-hush and the barn is closed on days when they’re there,” she says.

Lowe, who I saw ruling the stage as a rowdy ghost in Wellesley Theatre Project’s A Christmas Carol this past winter, is prepping to attend Savannah College of Art and Design with a major in performing arts and a minor in vocal performance after graduating from Wellesley High. She acknowledges the irony in her horse’s star turn: “I always joke about how my horse is getting his big movie break before I get mine since I’m looking to become an actor.”